JP7378491B2 - Medical treatment systems, methods, and devices using multiple fluid lines - Google Patents

Description

Peritoneal dialysis (PD) requires the periodic injection of a sterile aqueous solution (called peritoneal dialysis fluid or dialysate) into a patient's peritoneal cavity. Diffusion and osmotic exchange takes place between solutions and the bloodstream across autologous body membranes. These exchanges transport waste products to the dialysate, which is normally excreted by the kidneys. Waste products usually consist of solutes such as sodium and chloride ions, and other compounds that are normally excreted through the kidneys, such as urea, creatinine and water. The diffusion of water across the peritoneum during dialysis is called ultrafiltration.

Conventional peritoneal dialysis fluid contains a sufficient concentration of glucose to generate the osmotic pressure necessary to remove water from the patient through ultrafiltration.

Continuous ambulatory peritoneal dialysis (CAPD) is a common form of PD. Patients perform CAPD manually approximately four times a day. During a drain/fill procedure for CAPD, the patient first drains the used peritoneal dialysate from his peritoneal cavity and then injects fresh peritoneal dialysate into his peritoneal cavity. This drain and fill procedure typically takes about an hour.

Automated peritoneal dialysis (APD) is another form of PD. APD uses a machine called a cycler to automatically inject peritoneal dialysis fluid into the patient's peritoneal cavity, allow it to dwell, and drain the peritoneal cavity. APD is particularly attractive for PD patients because it can be performed at night while the patient is asleep. This eliminates the need for the patient to perform CAPD every day while the patient is awake and working.

APD procedures typically last several hours. It often begins with an initial drainage phase that empties the used dialysate from the peritoneal cavity. The APD procedure then continues through successive fill, dwell and drain phases that occur in sequence. Each fill/dwell/drain procedure is called a cycle.

During the filling phase, the cycler delivers a predetermined volume of fresh, warmed dialysate into the patient's peritoneal cavity. The dialysate remains within the peritoneal cavity (ie, "settles") for a period of time. This is called the residence stage. During the drainage phase, the cycler removes used dialysate from the peritoneal cavity.

The number of fill/dwell/drain cycles required during a given APD session is determined by the total volume of dialysate prescribed for the patient's APD regimen, and may be entered as part of the treatment prescription or Calculated by cycler.

APD can and is implemented in a variety of ways.

Continuous ambulatory peritoneal dialysis (CCPD) is one commonly used APD modality. During each fill/dwell/drain phase of the CCPD, the cycler infuses the prescribed volume of dialysate. After a defined dwell period, the cycler drains this fluid volume completely from the patient, emptying or "drying" the peritoneal cavity. Typically, CCPDs employ four to eight fill/dwell/drain cycles to achieve the prescribed treatment volume.

After the last prescribed fill/dwell/drain cycle in the CCPD, the cycler injects the final fill volume. The final filled volume remains in the patient's body for an extended period of time. It is drained at the beginning of the next CCPD session in the evening or during daytime exchanges. The final fill volume may contain a different concentration of glucose than the fill volumes of successive CCPD fill/dwell/drain fill cycles provided by the cycler.

Intermittent peritoneal dialysis (IPD) is another APD modality. IPD is typically used in emergencies when a patient suddenly enters dialysis treatment. IPD can also be used when a patient needs PD, but cannot take on the responsibility of CAPD or can do it at home.

Like CCPD, IPD involves a series of fill/dwell/drain cycles. Unlike CCPD, IPD does not include a final filling step. In IPD, the patient's peritoneal cavity remains free of dialysate (or "dry") between APD treatment sessions.

Tidal peritoneal dialysis (TPD) is another APD modality. Like CCPD, TPD involves a series of fill/dwell/drain cycles. Unlike CCPD, TPD does not completely drain dialysate from the peritoneal cavity during each drainage step. Instead, the TPD establishes a basal volume during the first filling phase and drains only a portion of this volume during the first draining phase. The subsequent fill/dwell/drain cycle injects and then drains the base volume plus the exchange volume. The final drainage step removes all dialysate from the peritoneal cavity.

There are variations of TPD that involve cycles in which the patient is completely drained and a new full basal volume of dialysate is injected.

TPD, like CCPD, can include a final fill cycle. Alternatively, TPD can avoid the final fill cycle like IPD.

APD provides flexibility and improved quality of life for those who require dialysis. APD can relieve patients from the fatigue and inconvenience that the daily performance of CAPD presents to some. The APD can return to the patient the patient's waking and working hours without the need to perform dialysate exchanges.

Embodiments of the present disclosure provide a capacitance measurement standard set or cycler substantially as shown and described herein.

According to another embodiment of the present disclosure, a volumetric standard set for calibration of a cassette-based pump system may include a rigid body configured to seal installed within the cassette-based pump system. The rigid body may have a central body and a plurality of solid pump chamber regions each having a predefined shape defining a known volume of the pump chamber region. Rigid bodies may lack channels and orifices

In some embodiments, the capacitance measurement standard set can be metal. In some embodiments, a set of capacitance measurement standards can be machined. In some embodiments, the capacitance measurement standard set may be made from a list of materials consisting of aluminum, steel, and plastic. In some embodiments, a volumetric standard set may be constructed through a material addition process. In some embodiments, the central body may have a thickness that is at least half the thickness of the thickest portion of the rigid body. In some embodiments, the central body may have a thickness equal to at least 60% of the thickest portion of the rigid body. In some embodiments, the central body may have a thickness ranging from one-half to three-quarters of the thickest portion of the rigid body. In some embodiments, the volumetric standard cassette does not include a cassette sheet.

According to another embodiment of the present disclosure, a volumetric standard cassette for calibration of a cassette-based pump system has a central body that can be completely solid and that can include a first surface and an opposing second surface. may include. The volumetric standard cassette may further include a number of walls extending from at least the first side of the central body, including a peripheral wall located at the periphery of the central body as well as several interior walls. The volumetric standard cassette may further include a number of solid pump chamber regions each having a predefined shape defining a known volume of the pump chamber region. Volumetric standard cassettes may not be able to pump liquids.

In some embodiments, the sheet must not be bonded to any number of walls of the volumetric standard cassette. In some embodiments, the first side of the central body may be uncovered by a cassette sheet and may include a pump chamber region. In some embodiments, both the first side and the opposite side of the centerbody may be uncovered by the cassette sheet. In some embodiments, a volumetric standard set can be created from a list of processes consisting of material addition processes, machining, and molding. In some embodiments, the capacitance measurement standard set may be made from a list of materials consisting of aluminum, steel, and plastic. In some embodiments, the opposite side of the volumetric standard cassette can be flat. In some embodiments, the first side of the volumetric standard cassette may include a number of protrusions that may be surrounded by walls of the inner wall. In some embodiments, the walls may be draft free.

According to another embodiment of the present disclosure, a cassette analog of a disposable pump cassette for calibration of a cassette-based pump system may include a central body having a first surface and an opposing second surface. The cassette analog may further include a number of sealing ribs on at least the first side. The cassette analog may further include a first pump chamber region and a second pump chamber region. Each of the first and second pump chamber regions may have a defined, dimensionally stable shape representing a selected fill level of the corresponding pump chamber within the disposable pump cassette. The first side and the opposite side may be open sides or have no overlying cassette sheet. Cassette analogs may not be able to pump liquids.

In some embodiments, the cassette analog may be formed of metal. In some embodiments, the midbody can be completely solid. In some embodiments, the midbody may lack any passages. In some embodiments, the selected fill volume may be the full pump chamber volume of the corresponding pump chamber within the disposable pump cassette. In some embodiments, the selected fill volume may be the empty pump chamber volume of the corresponding pump chamber within the disposable pump cassette. In some embodiments, the selected fill volume may be an intermediate volume between the full pump chamber volume and the empty pump chamber volume of the corresponding pump chamber within the disposable pump cassette. In some embodiments, the opposite side of the volumetric standard cassette can be flat. In some embodiments, the first side of the volumetric standard cassette may include a number of protrusions surrounded by sealing ribs. The number of protrusions can be placed in positions corresponding to the number of valve seats on the disposable pump cassette. In some embodiments, the cassette analog may lack ports, spikes, and attached fluid lines.

According to another embodiment of the present disclosure, a method for calibrating a cassette-based pump system may include sequentially installing several volumetric calibration cassettes in the cassette-based pump system. Each of the number of volumetric calibration cassettes may include a pump chamber region having a known volume. The method may further include measuring a known volume of a pump chamber region within each volumetric calibration cassette using the cassette-based pump system. The method includes volumetric measurements performed in a cassette-based pump system based at least in part on a known volume for each of a number of volumetric calibration cassettes and a corresponding measured volume of a pump chamber area for each volumetric calibration cassette. The method may further include generating a calibration curve for the method.

In some embodiments, measuring the known volume of the pump chamber region in each volumetric calibration cassette includes making multiple measurements of the known volume of the pumping chamber region of each volumetric calibration cassette, and obtaining multiple measurements. may include analyzing. Determine a single value of the volume of the pump chamber area, which serves as the corresponding measured volume. In some embodiments, analyzing multiple measurements may include averaging the multiple measurements. In some embodiments, generating a calibration curve may include generating an optimal equation. In some embodiments, generating a calibration curve may include generating an optimal polynomial. In some embodiments, the optimal polynomial may be a third order polynomial. In some embodiments, generating a calibration curve may include performing a least squares regression. In some embodiments, generating a calibration curve may include constraining at least one region of the curve to at least one limit. In some embodiments, the limit may be an acceptable range of differential values of points along at least one region. In some embodiments, generating the calibration curve may include imposing constraints on the derivative value (allowed at zero crossings of the calibration curve). Measuring the known volume of the chamber region may include making multiple measurements of the known volume of the pump chamber region of each volume calibration cassette and determining their suitability to predefined criteria, and The multiple measurements are analyzed to determine a single value of the volume of the pump chamber region that serves as the corresponding measured volume. In some embodiments, the predefined criteria In some embodiments, the predefined criterion can be an acceptable standard deviation. In some embodiments, the method eliminates volume measurement errors due to disposable pump cassettes. In some embodiments, the method may further include refining the calibration curve to a second calibration curve that accounts for the head height of the fluid source or destination. The calibration curve may further include refining the calibration curve to a calibration curve of the method.

According to another embodiment of the present disclosure, a cassette-based pump system may include a fluid treatment set that includes a pump cassette having a flexible membrane covering at least one pump chamber. The system may further include a cycler. The cycler may include a mounting location sized to receive the pump cassette and position the cassette relative to the control surface. The cycler may further include multiple pressure reservoirs. The cycler may further include a pressure delivery assembly for applying pressure from the pressure reservoir to the pump cassette to pump fluid through the cassette. The pressure delivery assembly includes, in addition to the pressure sensor, a control surface, a pneumatic channel, and a control chamber for actuating the flexible membrane and at least one reference chamber of known volume for measuring the volume of the pump chamber. may have. The pneumatic channel may be in selective communication with the pressure reservoir through a number of valves. The cycler receives data from the pressure sensor, determines a raw measured amount of fluid to be pumped via the data, and determines the raw measured amount of fluid to be pumped based at least in part on a cycler-specific calibration equation. A controller configured to adjust may further be included.

In some embodiments, the controller may be configured to adjust the raw measured volume of pumped fluid based at least in part on a cycler-specific calibration equation and a pump cassette volume error calibration equation. In some embodiments, the controller adjusts the raw measured amount of pumped fluid based at least in part on a cycler-specific calibration equation, a pump cassette volume error calibration equation, and a head height error calibration equation. may be configured to do so. In some embodiments, the cycler-specific calibration equation may be a polynomial optimized over a data set of test measurements of a series of volumetric standard cassettes. In some embodiments, the controller may be configured to adjust the raw measured amount of fluid pumped based on a second calibration equation that may be a function of a cycler-specific calibration equation. In some embodiments, the second equation may be a pump cassette volumetric error calibration equation. In some embodiments, the controller may be configured to adjust the raw measured amount of fluid pumped based on a third calibration equation that may be a function of the second calibration equation. In some embodiments, the second equation may be a pump cassette volume error calibration equation and the third equation may be a head height error calibration equation. In some embodiments, the second equation may be a head height error calibration equation and the third equation may be a pump cassette volume error calibration equation. In some embodiments, the controller may be configured to adjust the raw measured amount of pumped fluid based at least in part on the cycler-specific calibration equation and the second calibration equation. In some embodiments, the system may further include a database of pump cassette volume error calibration equations associated with the cassette-related unique identifier. In some embodiments, the cycler may further include a user interface, and the controller may be configured to receive a cassette-related unique identifier input via the user interface. The controller can be configured to communicate with the database to obtain a pump cassette volumetric error calibration equation associated with the cassette-related unique identifier input. A pump cassette volumetric error calibration equation associated with the cassette-related unique identifier input may be used as the second calibration equation. In some embodiments, the cycler may further include an imager. The controller is configured to determine cassette-related unique identifier data via the imager data and communicate with the database to obtain a pump cassette volumetric error calibration equation associated with the cassette-related unique identifier data. be able to. A pump cassette volumetric error calibration equation associated with cassette-related unique identifier data can be used as the second calibration equation. In some embodiments, the fluid treatment set may include a coded cassette-associated unique identifier.

According to another embodiment of the present disclosure, a cassette-based pump system includes a pump cassette having a flexible membrane covering at least one pump chamber and at least one cassette valve that gates fluid communication to a fluid reservoir. A fluid handling set including: The system can further include a cycler with a pressure delivery assembly having at least one pump control chamber for actuating a portion of a flexible membrane covering the at least one pump chamber. The pressure delivery assembly may further include at least one valve control chamber for actuating a portion of the flexible membrane covering the at least one cassette valve. The pressure delivery assembly may further include at least one pressure sensor in communication with the at least one pump control chamber. The cycler may further include a pressure reservoir in selective communication with at least one pump control chamber and at least one valve control chamber via a number of pressure supply valves. The cycler may further include a controller configured to receive data from the at least one pressure sensor. The controller further commands the at least one cassette valve open, monitors data from the at least one pressure sensor to identify the first and second pressure peaks, and determines the first and second pressure peaks based on the first and second pressure peaks. the head height of the fluid reservoir.

In some embodiments, the controller may be further configured to determine the length of the fluid line coupling the fluid reservoir to the cassette based on the time data associated with the first and second peaks. In some embodiments, the first peak may be an overshoot peak and the second peak may be an undershoot peak. In some embodiments, the controller may be further configured to adjust operating parameters based on the calculated head height. In some embodiments, the operating parameter can be at least one pump pressure. In some embodiments, the controller may be further configured to refine the calibration curve based on head height. In some embodiments, the fluid reservoir can be a dialysate reservoir. In some embodiments, the fluid reservoir can be a body cavity of the patient. In some embodiments, the controller is further configured to displace a portion of the flexible membrane covering the at least one pump chamber to an intermediate stroke position before commanding the at least one cassette valve open. can be done. In some embodiments, the controller is further configured to determine a number of extension lines included in the fluid line coupling the fluid reservoir to the cassette based on the time data associated with the first and second peaks. can be done. In some embodiments, the controller may be further configured to generate an error when the head height exceeds a threshold. In some embodiments, the controller may be further configured to compare the head height to a predefined allowable head height threshold.

According to another embodiment of the present disclosure, a method of selecting a pump pressure for a cassette-based pump system may include priming a fluid treatment set installed in the pump system. The method may further include positioning a pump chamber of the cassette of the fluid treatment set in communication with the reservoir. The method may further include detecting a first pressure peak in a control chamber separated from the pump chamber by a membrane. The method may further include detecting a second pressure peak within the control chamber. The method may further include predicting final pressure using the first and second pressure peaks. The method may further include calculating a pump pressure based on the predicted final pressure.

In some embodiments, the method may further include calculating a reservoir head height based on the predicted final pressure. In some embodiments, the method may further include determining a characteristic length of a fluid line coupling the reservoir to the cassette-based time data associated with the first and second peaks. In some embodiments, the method further includes determining a number of extensions included in the fluid pathway coupling the cassette to the reservoir based on the time data associated with the first and second peaks. obtain. In some embodiments, the method may further include generating an error if the predicted final pressure exceeds a predetermined threshold. In some embodiments, the method may further include moving the membrane to a predetermined initial position. In some embodiments, the predetermined initial position may be a position that biases the head height detection range toward positive head height detection. In some embodiments, the predetermined initial position may be a position that biases the head height detection range toward negative head height detection. In some embodiments, the predetermined initial position may be a mid-stroke position. In some embodiments, the method may further include adjusting a calibration curve for the cassette-based pump system based on the predicted final pressure. In some embodiments, detecting the first peak may include calculating a difference between a set of consecutive data points from at least one pressure sensor in communication with the control room. In some embodiments, detecting the first peak may further include applying data smoothing to the set of consecutive data points forming the at least one pressure sensor. In some embodiments, the method may further include identifying a first peak if the difference between successive sets of data points is less than a predefined limit. In some embodiments, predicting the final pressure may include determining a percent overshoot based on the first and second peaks.

According to another embodiment of the present disclosure, a method for checking the head height of a reservoir coupled to a cassette-based pump system includes: may include arranging to communicate with. reservoir. The method may further include detecting a first pressure peak in a control chamber separated from the pump chamber by a membrane. The method may further include detecting a second pressure peak within the control chamber. The method may further include predicting final pressure using the first and second pressure peaks. The method may further include comparing the predicted final pressure to at least one predetermined threshold. The method may further include generating a notification when the predicted final pressure exceeds at least one of the at least one predetermined threshold.

In some embodiments, generating a notification may include generating an error. In some embodiments, generating the notification may include generating a screen for display on a user interface of the cassette-based pump system. In some embodiments, generating the notification may include generating an audible noise. In some embodiments, the method may further include calculating a reservoir head height based on the predicted final pressure. In some embodiments, the method may further include determining an overshoot percentage based on the first and second pressure peaks. In some embodiments, the method may further include determining a characteristic length of a fluid line coupling the reservoir to the cassette based on the time data associated with the first and second peaks. In some embodiments, the method further includes determining a number of extensions included in the fluid pathway coupling the cassette to the reservoir based on the time data associated with the first and second peaks. obtain. In some embodiments, the method may further include moving the membrane to a predetermined initial position. In some embodiments, the predetermined initial position may be a position that biases the head height detection range toward positive head height detection. In some embodiments, the predetermined initial position may be a position that biases the head height detection range toward negative head height detection. In some embodiments, the predetermined initial position may be a mid-stroke position. In some embodiments, the method may further include adjusting a calibration curve for the cassette-based pump system based on the predicted final pressure. In some embodiments, detecting the first peak may include calculating a difference between a set of consecutive data points from at least one pressure sensor in communication with the control room. In some embodiments, detecting the first peak may further include applying data smoothing to the set of consecutive data points from the at least one pressure sensor. In some embodiments, the method may further include identifying a first peak if the difference between successive sets of data points is less than a predefined limit.

According to another embodiment of the present disclosure, a cassette-based pump system includes a pump cassette having a flexible membrane covering at least one pump chamber and at least one cassette valve that gates fluid communication to a fluid reservoir. A fluid handling set including: The system can further include a cycler that includes at least one pump control chamber. The cycler may further include at least one valve control chamber. The cycler may further include at least one pressure sensor in communication with the at least one pump control chamber. The cycler may further include a pressure reservoir in selective communication with at least one pump control chamber and at least one valve control chamber via a number of pressure supply valves. The cycler may further include a controller in data communication with the pressure sensor. The controller commands the at least one cassette valve open, monitors data from the at least one pressure sensor, identifies first and second pressure peaks, and determines the first and second pressure peaks based on the first and second pressure peaks. It may be configured to predict final pressure.

In some embodiments, the controller may be further configured to determine the length of the fluid line coupling the fluid reservoir to the cassette based on the time data associated with the first and second peaks. In some embodiments, the first peak can be an overshoot peak and the second peak is an undershoot peak. In some embodiments, the controller may be further configured to adjust operating parameters based on the calculated head height. In some embodiments, the operating parameter can be at least one pump pressure. In some embodiments, the controller may be further configured to refine the calibration curve based on head height. In some embodiments, the fluid reservoir can be a dialysate reservoir. In some embodiments, the fluid reservoir can be a body cavity of the patient. In some embodiments, the controller is further configured to displace a portion of the flexible membrane covering the at least one pump chamber to an intermediate stroke position before commanding the at least one cassette valve open. can be done. In some embodiments, the controller is further configured to determine a number of extension lines included in the fluid line coupling the fluid reservoir to the cassette based on the time data associated with the first and second peaks. can be done. In some embodiments, the controller may be further configured to generate an error when the predicted final pressure exceeds a threshold. In some embodiments, the controller may be further configured to compare the predicted final pressure to a predefined allowable head height pressure threshold.

According to another embodiment of the present disclosure, a fluid line condition detector may include a receptacle configured to hold a fluid line that is opaque to ultraviolet light. The fluid line condition detector may further include an optical sensor. The fluid line condition detector may further include an infrared emitting LED. The fluid line condition detector may further include an ultraviolet emitting LED. The fluid line status detector may further include a third LED. The fluid line condition detector may further include a controller in data communication with the optical sensor. The controller is configured such that the intensity of the infrared rays sensed by the optical sensor from the infrared emitting LED exceeds a predetermined first threshold, and the intensity of the ultraviolet rays sensed by the optical sensor from the ultraviolet emitting LED falls below a predetermined second threshold. At times, a fluid line condition detector may be configured to determine that a suitable tube is present. The axis of the infrared emitting LED and the axis of the ultraviolet emitting LED can be parallel to each other and to the axis of the optical sensor.

In some embodiments, the axis of the infrared emitting LED can be the optical axis of the infrared emitting LED, and the axis of the ultraviolet emitting LED can be the optical axis of the ultraviolet emitting LED. In some embodiments, the axis of the infrared emitting LED can be the mechanical axis of the infrared emitting LED, and the axis of the ultraviolet emitting LED can be the mechanical axis of the ultraviolet emitting LED. In some embodiments, the axis of the optical sensor may be the optical axis of the optical sensor. In some embodiments, the optical sensor axis is the optical sensor mechanical axis. In some embodiments, the third LED can be an infrared emitting LED. In some embodiments, the axis of the third LED may be at an angle other than parallel to the axis of the infrared emitting LED and the axis of the ultraviolet emitting LED. In some embodiments, the axis of the ultraviolet emitting LED may be configured to pass through a central portion of a fluid line installed within the receptacle. In some embodiments, the receptacle may include a retainer to retain the fluid line. In some embodiments, the controller may be further configured to determine that the fluid line is dry when the light intensity from the third LED exceeds a predetermined dryness threshold. In some embodiments, the controller may be further configured to determine that the fluid line is primed when the light intensity from the third LED is below a predetermined primed threshold. The predetermined prime threshold may be lower than the predetermined desiccation threshold. In some embodiments, the controller activates the fluid when the light intensity from the infrared emitting LED falls below a predetermined infrared light threshold and when the light intensity from the third LED falls below a predetermined priming threshold. The line may be further configured to determine that the line is primed. The predetermined prime threshold may be lower than the predetermined desiccation threshold. In some embodiments, the controller causes the intensity of the ultraviolet radiation sensed by the optical sensor from the ultraviolet emitting LED to exceed a predetermined first threshold if the intensity of the infrared radiation sensed by the optical sensor from the infrared emitting LED exceeds a predetermined first threshold. determining that a suitable tube is present in the fluid line condition detector if below a second threshold and if the intensity of light emitted by the third LED is below a predetermined third threshold; can be configured. In some embodiments, the controller may be further configured to manage the provision of power to the infrared emitting LED, the ultraviolet emitting LED, and the third LED.

According to one embodiment of the present disclosure, fluid line condition detection for detecting the presence of a fluid line that is opaque to a first spectrum of light and at least translucent to a second spectrum of light. The vessel may include a receptacle configured to hold the fluid line. The fluid line condition detector may further include an optical sensor. The fluid line condition detector may further include a first LED configured to emit light in a first spectrum. The fluid line condition detector may further include a second LED configured to emit light of a second spectrum. The fluid line status detector may further include a third LED. The fluid line condition detector may further include a controller in data communication with the optical sensor. The controller controls when the intensity of the first spectrum of light sensed by the light sensor from the first LED is below a predetermined first threshold; may be configured to determine that a fluid line is present in the fluid line status detector when the intensity of the light of the fluid line status detector exceeds a predetermined second threshold. The axis of the first LED and the axis of the second LED may be parallel to each other and to the axis of the optical sensor.

In some embodiments, the first LED axis can be the first LED optical axis and the second LED axis can be the second LED optical axis. In some embodiments, the first LED axis can be the first LED mechanical axis and the second LED axis can be the second LED mechanical axis. In some embodiments, the axis of the optical sensor may be the optical axis of the optical sensor. In some embodiments, the optical sensor axis can be the optical sensor mechanical axis. In some embodiments, the third LED may be configured to emit light in a second spectrum. In some embodiments, the axis of the third LED may be at an angle other than parallel to the axis of the first LED and the axis of the second LED. In some embodiments, the axis of the first LED may be configured to pass through a central portion of the fluid line when the fluid line is installed within the receptacle. In some embodiments, the receptacle may include a retainer to retain the fluid line. In some embodiments, the controller may be further configured to determine that the fluid line is dry when the light intensity from the third LED exceeds a predetermined dryness threshold. In some embodiments, the controller may be further configured to determine that the fluid line is primed when the light intensity from the third LED is below a predetermined primed threshold. The predetermined prime threshold may be lower than the predetermined desiccation threshold. In some embodiments, the controller controls when the light intensity from the second LED falls below a predetermined second light spectrum threshold and when the light intensity from the third LED falls below a predetermined priming threshold. The fluid line may be further configured to determine that the fluid line is primed. The primed threshold is less than the predetermined desiccation threshold. In some embodiments, the controller detects the light intensity sensed by the light sensor from the second LED when the light intensity of the first spectrum sensed by the light sensor from the first LED is below a predetermined first threshold. If the light intensity of the second spectrum detected exceeds a predetermined second threshold and the light intensity sensed by the optical sensor from the third LED is below a predetermined third threshold, the fluid line is in a fluid line state. The detector may be configured to determine the presence of the detector. In some embodiments, the controller may be further configured to manage the provision of power to the first, second, and third LEDs. In some embodiments, the first spectrum can be an ultraviolet spectrum. In some embodiments, the second spectrum can be an infrared spectrum. In some embodiments, the fluid line may be transparent to the second spectrum of light.

According to one embodiment of the present disclosure, a method of detecting the presence of a suitable fluid line within a receptacle of a detector may include emitting light of a first spectrum from a first LED. The fluid line may be opaque to the first spectrum of light. The method may further include emitting a second spectrum of light from the second LED. The fluid line may be at least translucent to light of the second spectrum. The method may further include monitoring the intensity of the received light with a light sensor located on an opposite side of the receptacle than the first and second LEDs. The method may further include comparing the intensity of light received in the first spectrum to a first threshold. The method may further include comparing the intensity of light received in the second spectrum to a second threshold. The method includes determining the presence of a suitable fluid line if the intensity of light in a first spectrum is less than a first threshold and the intensity of light in a second spectrum is greater than a second threshold. may further include.

In some embodiments, the first threshold may correspond to substantially no light transmission from the first LED to the optical sensor. In some embodiments, the first spectrum can be an ultraviolet spectrum. In some embodiments, the second spectrum can be a higher wavelength spectrum than the first spectrum. In some embodiments, the second spectrum can be an infrared spectrum. In some embodiments, the fluid line may be transparent to the second spectrum of light. In some embodiments, the method generates a notification when the intensity of light in the first spectrum is greater than a first threshold and the intensity of light in the second spectrum is greater than a second threshold. may further include. In some embodiments, generating the notification may include displaying a notification to reload the fluid line on the graphical user interface. In some embodiments, the axes of the first LED and the second LED can be parallel to each other and to the axis of the optical sensor.

According to one embodiment of the present disclosure, a fluid pumping system may include a pump. The fluid pump system may further include a displacement volume sensing assembly. The fluid pump system may further include a receptacle for holding the fluid line, at least one optical sensor, and a fluid line status detector having at least one LED. The fluid pump system may further include a fluid transfer set including an output line configured to mate with the receptacle. The fluid pump system may further include at least one fluid source. The fluid pump system may further include a controller in data communication with the fluid line condition detector. The controller may be configured to power the at least one LED and monitor the output signal of the at least one light sensor when the outlet line is installed in the receptacle to determine a light intensity value for the dry tube. . The controller can be further configured to control operation of the pump to prime the output line with fluid from the at least one fluid source. The controller is further configured to power the at least one LED, monitor the output signal, and stop operation of the pump when the output signal indicates that the light intensity value falls below the primed line threshold. can be configured. The primed line threshold may be calculated by the controller based on dry tube intensity readings.

In some embodiments, the primed line threshold may be calculated by adding a constant to the percentage of the dry tube intensity value. In some embodiments, the controller may be further configured to power the at least one LED multiple times. The dry tube intensity value can be based on the maximum light intensity value output from the optical sensor over multiple times. In some embodiments, the controller may be configured to power the at least one LED multiple times and monitor the output signal to determine the maximum light intensity value. The dry tube intensity value can be based on a maximum light intensity value and at least one limit. In some embodiments, the limit may be a minimum dry tube strength value. In some embodiments, the controller may be further configured to generate a notification when the displaced fluid sensing assembly indicates that the volume of displaced fluid is greater than a predefined threshold. In some embodiments, the controller may be configured to continue pumping upon receipt of user input from the system's user interface indicating that the output line is not yet fully primed. In some embodiments, the pump can be a diaphragm pump. In some embodiments, the pump may be a pneumatic diaphragm pump. In some embodiments, a portion of the pump may be included in a fluid transfer set. In some embodiments, a portion of the pump may be included in a fluid treatment cassette of a fluid transfer set. In some embodiments, a fluid transfer set may include a fluid handling cassette with at least one pump chamber, each of the at least one pump chamber forming part of a pump. In some embodiments, at least one fluid source can be a dialysate reservoir. In some embodiments, the at least one LED may include a first LED positioned at an angle to the optical axis of the photosensor. In some embodiments, the at least on LEDs may include a second LED and a third LED. In some embodiments, the axis of the second LED and the axis of the third LED may be parallel to the optical axis of the photosensor.

According to another embodiment of the present disclosure, a method of priming a fluid line may include installing the fluid line into a receptacle of a fluid line condition detector. The method may further include emitting light from at least one LED of the fluid line condition detector a first plurality of times. The method may further include monitoring an output signal of a light sensor of the fluid line condition detector and determining a maximum light intensity value based on the output signal during the first plurality of times. The method may further include determining a threshold for the primed line based on the maximum light intensity value. The method may further include pumping fluid through the fluid line. The method may further include emitting light from at least one LED of the fluid line condition detector a second plurality of times. The method may further include determining that the fluid line is primed when the output signal of the optical sensor indicates that the light intensity from the LED has exceeded a threshold of the primed tube.

In some embodiments, installing the fluid line into the receptacle may include seating the fluid line within a channel of a fluid line condition detector. In some embodiments, the method may further include comparing the maximum light intensity to a limit and overwriting the maximum light intensity value with the value of the limit if the maximum light intensity value does not comply with the limit. In some embodiments, determining the maximum light intensity value based on the output signal includes comparing the light intensity value indicated by the output signal during the first plurality of times with a calibration value to determine a ratio. may include doing. In some embodiments, the calibrated value may be a light intensity value from the at least one LED output from the optical sensor when the tube is not attached to the receptacle. In some embodiments, determining the primed line threshold may include adding a constant to a percentage of the maximum light intensity value. In some embodiments, the second plurality of times may occur during the process of pumping fluid through the line. In some embodiments, emitting light from the at least one LED during the second plurality of times may include emitting light from the first, second, and third LEDs. In some embodiments, the method may further include stopping pumping of fluid through the line when determining that the fluid line has been primed. In some embodiments, the method may further include monitoring the volume of fluid pumped through the displaced volume sensing assembly. In some embodiments, the method may further include suspending pumping of fluid when the amount of fluid pumped exceeds a first amount threshold. In some embodiments, the method may further include resuming pumping upon receiving user input indicating that the line is not yet fully primed. In some embodiments, the method may further include inhibiting restart of the pump if the amount of fluid pumped exceeds a second amount threshold.

According to another embodiment of the present disclosure, a fluid pumping system may include a pump. The fluid pump system may further include a fluid line condition detector having a receptacle, at least one sensor, and at least one illuminator. The fluid pump system may further include a fluid transfer set including an output line configured to mate with the receptacle. The fluid pump system may further include a controller in data communication with the fluid line condition detector. The controller may be configured to power the at least one illuminator and monitor the output signal of the at least one sensor when the exit line is installed in the receptacle to determine a light intensity value for the dry tube. . The controller can be further configured to control operation of the pump to prime the output line with fluid from the at least one fluid source. The controller further powers the at least one illuminator, monitors the output signal, and operates the pump when the output signal indicates that the light intensity value falls below a prime line threshold that depends on the dry tube intensity value. may be configured to stop.

In some embodiments, the primed line threshold may be calculated by adding a constant to a percentage of the dry tube light intensity value. In some embodiments, the controller may be configured to power the at least one illuminator multiple times, and the dry tube light intensity value is based on the maximum light intensity value output from the sensor over the multiple times. In some embodiments, the controller may be configured to power at least one illuminator multiple times and monitor the output signal to determine a maximum light intensity value, wherein the dry tube light intensity value is , a maximum light intensity value and at least one limit. In some embodiments, the limit may be a minimum dry tube light intensity value. In some embodiments, the system may further include a displacement volume sensing assembly. The controller can be further configured to generate a notification when the displaced volume sensing assembly indicates that the displaced fluid volume is greater than a predefined threshold. In some embodiments, the controller may be configured to continue pumping upon receipt of user input from the system's user interface indicating that the output line is not yet fully primed. In some embodiments, the pump can be a diaphragm pump. In some embodiments, the pump may be a pneumatic diaphragm pump. In some embodiments, a portion of the pump may be included in a fluid transfer set. In some embodiments, at least one fluid source can be a dialysate reservoir. In some embodiments, at least one illuminator may include a first LED positioned at an angle to the optical axis of the sensor. In some embodiments, at least one illuminator may include a second LED and a third LED. In some embodiments, the axis of the second LED and the axis of the third LED may be parallel to the optical axis of the sensor.

Aspects of the invention are described below, at least in part, with reference to exemplary embodiments illustrated in the following drawings. In the drawings, like numbers refer to like elements.
1 shows a schematic diagram of an automated peritoneal dialysis (APD) system incorporating one or more aspects of the present invention. 1B shows an alternative configuration to the dialysate delivery set shown in FIG. 1A. 2 is a schematic diagram of an exemplary set used in the APD system of FIG. 1; FIG. FIG. 2 is an exploded perspective view of the cassette in the first embodiment. 4 is a cross-sectional view of the cassette taken along line 4-4 in FIG. 3. FIG. FIG. 2 is a perspective view of a vacuum forming mold that may be used to form a membrane with a preformed pump chamber portion in an exemplary embodiment. 4 shows a front view of the cassette body of FIG. 3. FIG. FIG. 6 is a front view of a cassette body including two different spacer arrangements in an exemplary embodiment. FIG. 4 is a rear perspective view of the cassette body of FIG. 3; FIG. 4 is a rear view of the cassette main body of FIG. 3; 1 is a front perspective view of an exemplary configuration of a fluid line condition detector or liquid level detector; FIG. FIG. 3 is a rear perspective view of a fluid line condition detector or liquid level detector. FIG. 3 is a perspective layout of three LEDs and an optical detector surface mounted on a printed circuit board. FIG. 3 is a top view of three LEDs and an optical detector mounted on a detector circuit board. 11 is an exploded perspective view of the detector of FIG. 10 showing the printed circuit board and transparent or translucent plastic insert; FIG. 11 is a graph illustrating that the liquid level detector of FIG. 10 is capable of distinguishing between primed and unprimed fluid lines. Figure 3 is a graph showing measurements detected by an optical sensor comparing liquid detection using angled LEDs versus orthogonally oriented LEDs. 11 is a graph showing that the liquid level detector of FIG. 10 is capable of distinguishing between the presence and absence of a tube segment within the detector. 11 is a graph showing the range of signals corresponding to primed and unprimed fluid lines for various cyclers using the liquid detector of FIG. 10; FIG. 2 is a flowchart depicting several example actions that may be performed to prime a fluid line. FIG. 3 is a perspective view of an alternative configuration of a liquid level detector. FIG. 7 illustrates an embodiment of a fluid line cap, fluid line, and fluid line connector. FIG. 7 illustrates an embodiment of a fluid line cap, fluid line, and fluid line connector. Figure 3 illustrates another embodiment of a fluid line cap, fluid line and fluid line connector. Figure 3 illustrates another embodiment of a fluid line cap, fluid line and fluid line connector. Figure 3 shows an example of a fluid line cap that includes a cutout. FIG. 7 shows an example of a fluid line cap that includes a restriction. FIG. 27 shows a cross-sectional view of the fluid line cap at line 26-26 of FIG. 26. FIG. Figure 3 shows an example of a fluid line cap installed on a fluid line connector of a fluid line. 28 shows a cross-sectional view of the fluid line cap, fluid line, and fluid line connector of FIG. 27 taken at line 28-28 of FIG. 28. Figure 3 shows a flowchart outlining several steps that a cycler can use to prime a line with a two-part prime. 2 is a perspective view of the APD system of FIG. 1 with the cycler door open; FIG. 32 is a front view of a control surface of a cycler for interacting with a cassette in the embodiment of FIG. 31; FIG. FIG. 3 is a front view of an embodiment of a control surface of a cycler. 33B shows selected cross-sectional views of FIG. 33A. 33B shows selected cross-sectional views of FIG. 33A. 33 is an exploded view of the assembly for the interface of FIG. 32 with mating pressure supply blocks and pressure distribution modules; FIG. Figure 3 shows an exploded view of the control gasket inserted between the pressure supply block of the base unit and the pump cassette. FIG. 3 is an exploded view of the integrated manifold. Figure 2 shows two isometric views of the integrated manifold. Figure 2 shows a schematic diagram of a pneumatic system that controls fluid flow through the cycler. FIG. 3 is a front side view of an embodiment of a cassette fixture. 4 shows another example of a cassette fixture made from a modified cassette, such as the cassette shown in FIG. 3; FIG. 7 shows another example of a cassette fixture made from a modified cassette cassette. Figure 3 shows pressure tracking from the control or actuation chamber of the pump cassette during the liquid delivery stroke. 2 is a schematic diagram of a pump chamber and associated control components and inlet/outlet passageways of a cassette in an exemplary embodiment; FIG. 44 is an exemplary pressure plot for the control and reference chambers from before valve X2 is opened to some time after valve X2 is opened, for the embodiment of FIG. 43; FIG. 2 is a schematic diagram of a control chamber of a cassette and associated control components including pressure sensors and inflow/outflow passages in an exemplary embodiment; FIG. 2 is a pressure versus time plot for the reference and control chambers during pumping and FMS processes. 2 is a flowchart of the pneumatic steps of the FMS process. Figure 3 is a plot of pump chamber and reference chamber pressure during the +FMS process. - Plot of pressure in the pump chamber and reference chamber during the FMS process. FIG. 2 is an illustration of a polytropic conceptual model of a +FMS process involving three separate closed mass systems. FIG. 4 is a plot of polytropic expansion constant for +FMS versus control room volume. FIG. FIG. 2 is an illustration of a polytropic conceptual model of the FMS process - including three separate closed mass systems. Figure 2 is a plot of polytropic expansion constant for -FMS versus control room mass. 3 is a flowchart of basic AIA FMS calculation steps; Figure 3 is a more detailed flowchart of the AIA FMS calculation steps. 1 is a flowchart of an FMS calibration method for a diaphragm pump. 5 is a flow chart for calibrating partial stroke volumes for the FMS calibration method; FIG. 2 is an illustration of a process used to calibrate partial stroke volumes in a diaphragm pump. FIG. 3 is an illustration of the correction of volumetric measurements during partial stroke calibration as the pump diaphragm approaches the chamber wall; Figure 3 shows pressure traces from the control or working chamber of the pump cassette during a liquid delivery stroke. FIG. 7 shows a graph plotting pressure in a control or working chamber during a liquid delivery stroke and a cumulative volume estimation plot during a liquid delivery stroke. FIG. 3 shows a flowchart outlining multiple steps that can be used to estimate control room volume changes over time. FIG. 3 shows a flowchart outlining multiple steps for adjusting the equation used to estimate control chamber volume change over time during a pump stroke. 2 shows a flowchart outlining multiple steps for detecting end of stroke based on flow rate during the stroke. FIG. 3 shows a flowchart outlining multiple steps for determining the end of a stroke by predicting the time required to complete the stroke. 2 shows a flowchart outlining multiple steps for detecting a reduced flow condition while a pump stroke is in progress. FIG. 3 illustrates a top view of an exemplary disposable fluid pump cassette. 63B shows a cross-sectional view taken along line 63B-63B of FIG. 63A. 63C shows a cross-sectional view taken along line 63C-63C of FIG. 63A. FIG. 3 shows a top view of an exemplary set of capacitance measurement standards. 64B shows a cross-sectional view taken along line 64B-64B of FIG. 64A. 64A shows a cross-sectional view taken along line 64C-64C of FIG. 64A. FIG. 2 shows a perspective view of an exemplary volumetric standard cassette. FIG. 3 shows a perspective view of another exemplary volumetric standard cassette. 65A shows a top view of the volumetric standard cassette shown in FIG. 65A. FIG. 3 shows a perspective view of another exemplary volumetric standard cassette. 66B shows a top view of the volumetric standard cassette shown in FIG. 66A. FIG. 3 shows a perspective view of another exemplary volumetric standard cassette. 67B shows a top view of the volumetric standard cassette shown in FIG. 67A. 65A illustrates a cross-sectional view of the exemplary capacitance measurement standard set shown in FIG. 65A. 66A illustrates a cross-sectional view of the exemplary capacitance measurement standard set shown in FIG. 66A. 67A illustrates a cross-sectional view of the exemplary capacitance measurement standard set shown in FIG. 67A. FIG. 3 shows a perspective view of another exemplary volumetric standard cassette. 69B shows a top view of the volumetric standard cassette shown in FIG. 69A. FIG. 3 shows a perspective view of another exemplary volumetric standard cassette. 70A shows a top view of the volumetric standard cassette shown in FIG. 70A. FIG. 3 shows a perspective view of another exemplary volumetric standard cassette. 71A shows a top view of the volumetric standard cassette shown in FIG. 71A. FIG. 3 shows a perspective view of another exemplary volumetric standard cassette. 72B shows a top view of the volumetric standard cassette shown in FIG. 72A. 69B illustrates a cross-sectional view of the exemplary capacitance measurement standard set shown in FIG. 69A. 70A shows a cross-sectional view of the exemplary capacitance measurement standard set shown in FIG. 70A. 71A illustrates a cross-sectional view of the exemplary capacitance measurement standard set shown in FIG. 71A. 72A illustrates a cross-sectional view of the exemplary capacitance measurement standard set shown in FIG. 72A. FIG. 5 depicts a flowchart detailing some example actions that may be performed to perform calibration with one or more volumetric calibration cassettes. FIG. 6 shows a graph showing an exemplary calibration curve for a control room of a cycler. FIG. 5 shows an exemplary graph showing several calibration curves that may be used by a cycler. FIG. 2 shows a flowchart illustrating some example actions that can be used to improve a cycler's calibration curve. FIG. 12 depicts a flowchart illustrating some example actions that may be used to refine a particular cycler's calibration curve based on information related to the disposable cassette that is about to be used in an impending treatment. FIG. 5 depicts a flowchart illustrating some example actions that may be used to test production lots of disposable cassettes during manufacturing. FIG. 5 depicts a flowchart detailing some example actions that may be performed to detect the head height of a component of interest in the system. FIG. 5 depicts a flowchart detailing several example actions that may be performed to adjust pump pressure based on the determined head height of the component of interest. FIG. 5 depicts a flowchart detailing some example actions that may be performed during head height detection of a component of interest in the system. FIG. 5 depicts a flowchart detailing some example actions that may be performed during head height detection of a component of interest in the system. Figure 3 shows representative views of the pump chamber after completing a delivery stroke to the destination at different head heights. Figure 3 shows representative views of the pump chamber after completing a delivery stroke to the destination at different head heights. FIG. 5 shows a flowchart detailing several actions that may be used to determine a calibration curve for a particular head height.

Automated Peritoneal Dialysis System FIG. 1A illustrates an automated peritoneal dialysis (APD) system 10 that incorporates one or more aspects of the disclosure. Illustrated and described in Norris et al., U.S. Patent No. 10,058,694 (Title: Medical Systems and Methods Using Multiple Fluid Lines) (Attorney Docket Number: Q21) filed June 5, 2015 Other APD systems, or components thereof, such as those described herein (incorporated herein by reference in their entirety) may also be used with various aspects of the disclosure detailed herein.

As shown in FIG. 1A, for example, system 10 in this exemplary embodiment interacts with dialysate delivery set 12 (which in some embodiments may be a disposable set) to A cycler 14 that pumps liquid provided by a container 20 (e.g., a bag) and a control system 16 (e.g., a programmed computer or other data processor, computer memory, user or including an interface that provides information to and receives input from other devices, one or more sensors, actuators, relays, pneumatic pumps, tanks, power supplies, and/or other suitable components, i.e., FIG. only a few buttons are shown for receiving user control inputs (more details regarding the control system components are discussed below). In this exemplary embodiment, cycler 14 and control system 16 are associated with a common housing 82, but may be associated with more than one housing and/or may be separate from each other. The cycler 14 can have a compact footprint suitable for operation on a table top or other relatively small surface typically found in the home. The cycler 14 is lightweight and portable, and can be held by hand, for example, via handles on either side of the housing 82.

Although set 12 is intended in this embodiment to be a single-use disposable item, it may instead have one or more reusable parts, or be entirely reusable. could be. Before starting each APD treatment session, the user associates the set 12 with the cycler 14, for example by installing the cassette 24 in the front door 141 of the cycler 14, and the cycler 14 interacts with the cassette 24 to It pumps and controls fluid flow in 12 different lines. For example, to perform APD, dialysate can be pumped to and from the patient. After treatment, the user may remove all or some of the components of set 12 from cycler 14.

Prior to use, the user can connect the patient line 34 of set 12 to his or her indwelling peritoneal catheter (not shown) at connection 36, as is known in the art. In one embodiment, cycler 14 can be configured to operate with one or more different types of cassettes 24, such as those having patient lines 34 of different sizes. For example, a first type of cassette with a patient line 34 that is sized for use with an adult patient, and a second type of cassette with a patient line 34 that is sized for infant or pediatric use. The cycler 14 can be configured as follows. Pediatric patient lines 34 can be shorter and have a smaller inner diameter than adult lines to minimize the volume of the line, allowing for more controlled delivery of dialysate, and ensuring that set 12 is continuous When used in drain and fill cycles, it helps avoid relatively large amounts of used dialysate from returning to the pediatric patient. A heater bag 22 can be placed above a heater container receiving portion (in this case, a tray) 142 of the cycler 14, which is connected to the cassette 24 by a line 26. The cycler 14 can pump fresh dialysate into the heater bag 22 (via the cassette 24), thereby allowing the dialysis fluid to be pumped into the heater bag 22 by the heater tray 142, e.g., by an electrical resistance heating element associated with the tray 142. The liquid can be heated to a temperature of about 37°C. Heated dialysate may be provided to the patient from heater bag 22 via cassette 24 and patient line 34. In an alternative embodiment, on the way to the patient, upon entering or exiting the cassette 24, the dialysate is passed through tubing that contacts the heater tray 142 or in series (which may be provided in the cassette 24). The dialysate can be heated by passing it through a fluid heater. Spent dialysate may be pumped from the patient to the cassette 24 via a patient line 34 and into a drain line 28, which allows flow through one or more branches of the drain line 28. may include one or more clamps to control the . In this illustrative embodiment, the drain line 28 includes a connector 39 that connects the drain line 28 to a dedicated drain receiver and a drain that obtains a sample of used dialysate for testing or other analysis. A sample port 282 may be included. The user can also install the line 30 of one or more containers 20 within the door 141. Line 30 can also be connected to a continuous or real-time dialysate dispensing system. (Lines 26, 28, 30, 34 may include flexible tubing and/or suitable connectors and other components (such as pinch valves) as desired). Container 20 contains sterile peritoneal dialysis fluid to be infused, or other substances (e.g., materials that cycler 14 uses to formulate dialysate by mixing with water or mixing different types of dialysate). can do. Line 30 can be connected to spike 160 of cassette 24, which is covered by a removable cap in FIG. 1A.

In one aspect of the invention, cycler 14 can automatically remove the cap from one or more spikes 160 of cassette 24 and connect line 30 of solution container 20 to the respective spike 160. This feature can help reduce the likelihood of infection or contamination by reducing the chance of contact with spikes 160 of non-sterile articles.

In another aspect, dialysate delivery set 12A may not have cassette spikes 160. Alternatively, one or more solution lines 30 can be permanently attached to the inlet port of cassette 24, as shown in FIG. 1B. In this case, each solution line 30 may have a spike connector 35 (with a cap) for manual connection to a solution container or dialysate bag 20.

By making the various connections, control system 16 can pace cycler 14 through a typical series of fill, dwell and/or drain cycles of an APD procedure. For example, during the fill phase, cycler 14 may pump (via cassette 24) dialysate from one or more containers 20 (or other dialysate source) into heater bag 22 to heat dialysate. Cycler 14 can then inject the heated dialysate from heater bag 22 through cassette 24 and into the patient's peritoneal cavity via patient line 34 . Following the dwell phase, cycler 14 may begin a drain phase during which cycler 14 pumps used dialysate from the patient via line 34 (also by cassette 24). The used dialysate is then drained into a nearby drain (not shown) via drain line 28.

The cycler 14 does not necessarily require that the solution container 20 and/or the heater bag 22 be positioned at a defined head height above the cycler 14, for example because the cycler 14 is not necessarily a gravity flow system. Alternatively, the cycler 14 may be configured to simulate gravity flow or otherwise, even if the source solution container 20 is above, below, or at the same height as the cycler 14, the patient is above or below the cycler, etc. The flow of dialysate can be suitably controlled by this method. For example, cycler 14 can mimic a fixed head height during a given procedure, or cycler 14 can increase or decrease the effective head height to increase or decrease the pressure applied to the dialysate during a procedure. Can be changed. Cycler 14 can also regulate the flow rate of dialysate. In one aspect of the invention, the cycler 14 adjusts the pressure and/or flow rate of dialysate as it is delivered to or withdrawn from the patient so as to reduce the patient's perception of the filling or draining action. can do. Such adjustments can be made during a single fill and/or drain cycle, or can be adjusted over different fill and/or drain cycles. In one embodiment, the cycler 14 may taper off the pressure used to withdraw spent dialysate from the patient near the end of the drain operation. The cycler 14 can establish an artificial head height and thus have the flexibility to interact with and adapt to the patient's particular physiology or relative height changes.

Cassette Cassette In one aspect of the invention, the cassette 24 can include patient lines and drainage lines that are separately occludable to the solution supply lines. That is, safety-critical flow to and from patient lines can be controlled, for example, by pinching the lines to stop flow without the need to occlude flow through one or more solution supply lines. can do. This feature allows for a simplified occluder device, which allows for occlusion with respect to only two lines, as opposed to occluding other lines that have little or no impact on patient safety. This is because it can be done. For example, in situations where the patient or drain connections are separated, the patient and drain lines can be occluded. However, the solution supply lines and/or heater bag lines may remain open to flow, allowing the cycler 14 to prepare for the next dialysis cycle, e.g., patient lines and drains. Separate occlusion of the line allows cycler 14 to continue pumping dialysate from one or more containers 20 to heater bag 22 or other solution containers 20 while ensuring patient safety. can be helpful.

In another aspect of the invention, the cassette has patient lines, drainage lines and heater bag lines on one side or part of the cassette, and one on the other side or part of the cassette, e.g. Or it can have multiple solution supply lines. Such an arrangement may allow for separate occlusion of patient lines, drainage lines or heater bag lines with respect to solution lines, as described above. Physically separating the lines attached to the cassette by type or function allows for more efficient control of interaction with lines of a given type or function. For example, such an arrangement may allow for a simplified occluder design, which occludes one, two or three of these lines rather than all lines leading to or from the cassette. This is because the force required to do so becomes smaller. Alternatively, this arrangement may allow for more efficient automatic connection of solution supply lines to the cassette, as described in more detail below. That is, the solution supply lines and their respective connections are located away from the patient lines, drain lines and/or heater bag lines so that the automatic decapping and connection device removes the cap from the cassette spike and removes the solution. The caps on the supply lines can be removed and the lines connected to their respective spikes without interference from patient lines, drainage lines or heater bag lines.

FIG. 2 depicts an exemplary embodiment of a cassette 24 incorporating aspects of the invention described above. In this embodiment, the cassette 24 has a generally planar body with the heater bag line 26, drain line 28 and patient line 34 connected to respective ports on the left end of the cassette body, and the right end of the cassette body connected to respective ports on the left end of the cassette body. , can include five spikes 160 to which solution supply lines 30 can be connected. In the arrangement shown in FIG. 2, each of the spikes 160 is covered by a spike cap 63, which can be removed to expose the respective spike and allow connection to the respective line 30. As mentioned above, the line 30 can be attached to one or more solution containers or other sources of substances, for example for use in dialysis and/or for prescription of dialysate, for sampling purposes, or for peritoneal equilibrium testing ( (PET examination), it can be connected to one or more collection bags.

3 and 4 show exploded views (perspective and top views, respectively) of cassette 24 in this exemplary embodiment. Cassette 24 is formed as a relatively thin, flat member having a generally planar shape and may include components molded, extruded, or otherwise formed from a suitable plastic, for example. In this embodiment, cassette 24 includes a base member 18 that serves as a frame or structural member for cassette 24 and that at least partially defines various flow passages, ports, valve portions, etc. Base member 18 may be molded or otherwise formed from a suitable plastic or other material, such as polymethyl methacrylate (PMMA) acrylic resin, or cyclic olefin copolymer/ultra low density polyethylene (COC/ULDPE). and can be relatively rigid. In embodiments, the ratio of COC to ULDPE may be approximately 85%/15%. FIG. 3 also shows a heater bag port (port 150), a drainage port (port 152), and a patient port (port 154) formed in base member 18. Each of these ports may be arranged in any suitable manner, such as, for example, with a center tube 156 extending from an outer ring or skirt 158, or only a center tube. Flexible tubing for each of heater bag line 26, drainage line 28, and patient line 34 connects to central tube 156 and can be engaged by outer ring 158, if present.

Base member 18 may be covered on both sides by membranes 15 and 16, e.g., a flexible polymeric film made from polyvinyl chloride (PVC), e.g., cast, extruded, or otherwise formed. can. Alternatively, for example, as a laminate of two or more layers of polycyclohexylene dimethylene cyclohexanedicarboxylate (PCCE) and/or ULDPE held together by a coextrudable adhesive (CXA). can be formed. In some embodiments, the film thickness can range from approximately 0.002 inches to 0.020 inches thick. In preferred embodiments, the thickness of the PVC-based membrane may range from approximately 0.012 inches to 0.016 inches thick, more preferably approximately 0.014 inches thick. In another preferred embodiment, such as a laminate sheet, the thickness of the laminate may range from approximately 0.006 inch to 0.010 inch thick, more preferably approximately 0.008 inch thick.

Together, membranes 15 and 16 can function to close or otherwise form a portion of the flow path in cassette 24 as well as open/close valve ports and/or It can also be moved or otherwise manipulated to function as part of a pump diaphragm, septum or wall that moves fluid. For example, membranes 15 and 16 may be disposed over base member 18 and attached to a rim around the periphery of base member 18 (e.g., with heat, adhesive, or (by sonic welding or other means). The membrane 15 may also be joined to other inner walls of the base member 18 , for example, inner walls forming various channels, or when the cassette 24 is suitably attached to the cycler 14 . can be pressed into sealing contact with the walls and other features of the Both membranes 15 and 16 may therefore be sealed to the peripheral rim of base member 18, for example, to help prevent leakage of fluid from cassette 24 when removed from cycler 14 after use. , the other portions of the base member 18 may be positioned without contacting them. A cassette 24 placed within the cycler 14 can be squeezed between opposing gaskets or other members such that the membranes 15 and 16 are in sealing contact with the base member 18 in the inner region of the periphery. are pressed to suitably seal the channels, valve ports, etc. from each other.

Other configurations for membranes 15 and 16 are also possible. For example, membrane 16 may be formed from a rigid sheet of material that is joined or otherwise integrated with body 18. Thus, membrane 16 need not necessarily be or include a flexible member. Similarly, the membrane 15 need not be flexible over its entire surface, but instead has one or more flexible portions, such as of the cassette 24, to allow pump and/or valve operation. one or more rigid portions to close the flow path. For example, it is possible that if the cycler 14 includes suitable members for sealing the passages, such as a cassette, control valves and pump functions, then the cassette 24 may not include the membrane 16 or membrane 15.

According to another aspect of the invention, the membrane 15 is formed to have a shape that closely matches the shape of the corresponding pump chamber 181 recess of the base 18 (“pump membrane”). For example, the membrane 15 is generally formed as a flat member having a thermoformed (or otherwise shaped) dome-like shape 151 that conforms in shape to the pump chamber recess of the base member 18. The dome-like shape of the preformed pump chamber portion 151 can be constructed, for example, by heating and forming the membrane on a vacuum mold of the type shown in FIG. As such, a vacuum can be applied through a collection of holes along the mold wall. Alternatively, the mold wall can be constructed from a porous gas permeable material, thereby allowing the molded membrane In one example, the molded membrane sheet 15 is trimmed while being attached to a vacuum mold. Sheet 15 is pressed against cassette body 18, joining them together. In one embodiment, membrane sheets 15, 16 are heat welded to cassette body 18. In this way, membrane 15 is attached to pump chamber 181. (e.g., while pumping fluid out of pump chamber 181, as shown in solid lines in FIG. 4), membrane 15 is maximally within pump chamber 181 and (in some cases) spacer element 50 both when moving into contact with the pump chamber 181 and when the membrane 15 is fully withdrawn from the pump chamber 181 (e.g., as shown in dashed lines in FIG. 4 when drawing fluid into the pump chamber 181). Pumping action can be provided without the need for stretching of the membrane 15 (or at least with minimal stretching of the membrane 15).Avoiding stretching of the membrane 15 reduces pressure surges in the fluid delivery pressure due to sheet stretching. or other changes and/or may help simplify control of the pump when attempting to minimize pressure fluctuations during pump operation (e.g., during extension). reducing the likelihood of membrane 15 failure (due to tearing of the membrane 15 resulting from stresses placed on the membrane 15); and/or increasing accuracy in pump delivery volume measurements, as discussed in more detail below. In one embodiment, the pump chamber portion 151 defines a volume that is about 85% to about 85% of the pump chamber volume, for example, if the pump chamber portion 151 defines a volume that is about 100% of the pump chamber volume. 110%, the pump chamber portion 151 can be formed to have a size (e.g., define a volume) that is 110%, such that the pump chamber portion 151 remains unstressed within the pump chamber 181 and with the spacer 50 while at rest. can be located in contact.

There may be several advantages to providing greater control of the pressure used to generate the liquid filling and delivery strokes within and outside the pump chamber. For example, during a drainage cycle, when the pump chamber draws fluid from the patient's peritoneal cavity, it may be desirable to apply the lowest possible negative pressure. The patient may be uncomfortable during the treatment drain cycle, in part due to the negative pressure being applied by the pump during the fill stroke. The additional control that a preformed membrane can provide over the negative pressure applied during the filling stroke can help reduce patient discomfort.

By using a pump membrane preformed to the contour of the cassette pump chamber, several other advantages can be realized. For example, the flow rate of liquid through the pump chamber can be made more uniform, which can apply a constant pressure or vacuum throughout the pump stroke, thereby simplifying the process of regulating the heating of the liquid. This is because it is possible. Furthermore, the influence of temperature changes within the cassette pump on the dynamics of displacing the membrane as well as on the accuracy of measuring the pressure within the pump chamber can be made smaller. Additionally, pressure spikes within the fluid line can be minimized. It may also be simpler to correlate the pressure measured by a pressure transducer on the control (eg pneumatic) side of the membrane with the actual pressure of the liquid on the pump chamber side of the membrane. This allows for more accurate head height measurements of the patient and fluid source bag prior to treatment, increases the sensitivity of detecting air within the pump chamber, and improves the accuracy of volume measurements. Additionally, eliminating the need to stretch the membrane may allow for the construction and use of chambers with larger volumes.

In this embodiment, cassette 24 includes a plurality of pump chambers 181 formed in base member 18, although one pump chamber or more than two pump chambers are possible. According to aspects of the invention, the inner wall of pump chamber 181 includes spacer elements 50 that are spaced apart from each other to prevent portions of membrane 15 from contacting the inner wall of pump chamber 181. The pump chamber 18 extends from the inner wall of the pump chamber 18 to aid in its operation. (As shown in the right pump chamber 181 in FIG. 4, the inner wall is defined by a side 181a and a bottom 181b. The spacer 50 extends upwardly from the bottom 181b in this embodiment; 181a or otherwise formed.) By preventing the membrane 15 from contacting the pump chamber walls, the spacer element 50 provides a dead space (or trap volume). It is possible to confine air or other gas within the pump chamber 181 and may serve to inhibit pumping of gas from the pump chamber 181 in some circumstances. In other cases, spacer 50 can aid in the movement of gas to the outlet of pump chamber 181, thereby allowing gas to be removed from pump chamber 181, for example, during priming. The spacer 50 may also help prevent the membrane 15 from sticking to the pump chamber walls even when the membrane 15 is pressed into contact with the gas spacer element 50 and/or may help prevent the flow from sticking to the pump chamber walls. 181. Furthermore, the spacer 50 helps prevent premature closure of the pump chamber outlet ports (openings 187 and/or 191) if the seat accidentally comes into non-uniform contact with the pump chamber walls. Further details regarding the construction and/or function of spacer 50 are provided in U.S. Pat. Nos. 6,302,653 and 6,382,923, both of which are incorporated herein by reference. be incorporated into.

In this embodiment, the spacer elements 50 are arranged in a type of "stadium seating" arrangement whereby the spacer elements 50 are arranged in a concentric elliptical pattern such that the ends of the spacer elements 50 As the distance from the center increases, the height of the inner wall from the bottom 181b increases, forming a semi-elliptical dome-shaped region (indicated by a dotted line in FIG. 4). By arranging the spacer element 50 such that the ends of the spacer element 50 form a semi-elliptical area defining a dome-shaped area in which the pump chamber portion 151 of the membrane 15 is intended to extend, the pump chamber 181 The desired volume of dead space can be allowed to minimize any reduction to the intended stroke volume. As shown in FIG. 3 (and FIG. 6), the "stadium seating" arrangement in which spacer elements 50 are placed can include an elliptical pattern of "aisles" or breaks 50a. Breaks (or passageways) 50A help maintain equal gas levels throughout the rows (gaps or dead spaces) 50B between spacer elements 50 as fluid is delivered from pump chamber 181. For example, if the spacer elements 50 were arranged in the stadium seating arrangement shown in FIG. In this case, the membrane 15 can bottom out on a spacer element 50 located at the outermost edge of the pump chamber 181 and in the air gap between this outermost spacer element 50 and the side 181a of the pump chamber wall. Contains any gas or liquid present. Similarly, if the membrane 15 bottoms out over any two adjacent spacer elements 50, any gas and liquid in the void between the elements 50 can become trapped. Such an arrangement allows air or other gas to be delivered to the center of pump chamber 181 while liquid remains in the outer rows at the end of the pump stroke. Providing breaks (or passageways) 50A or other fluid communication means between the voids between the spacer elements 50 helps maintain equal gas levels throughout the voids during the pump stroke, thereby ensuring that the liquid Air or other gas may be prevented from exiting the pump chamber 181 unless the volume is substantially delivered.

In some embodiments, the spacer elements 50 and/or the membrane 15 do not generally wrap around or otherwise wrap around the individual spacers 50 when the membrane 15 is pressed into contact with the gas spacer 50. The spacers 50 may be arranged so that they do not deform or otherwise significantly extend into the gaps between the pacers 50. Such an arrangement may reduce any stretch or damage to the membrane 15 caused by wrapping around or otherwise deforming around one or more individual spacer elements 50. For example, in this embodiment it has been found advantageous to have the size of the air gap between the spacers 50 approximately equal in width to the width of the gas spacer 50. This feature has been found to help prevent deformation of the membrane 15, such as sagging of the membrane into the air gap between the spacers 50, when the membrane 15 is forced into contact with the spacers 50 during the pumping operation. .

According to another aspect of the invention, the inner wall of the pump chamber 181 may define a recess that is larger than the space, for example a semi-elliptical or dome space, in which the pump chamber portion 151 of the membrane 15 is intended to extend. In such a case, one or more spacer elements 50 may be placed below the dome-shaped area in which the membrane portion 151 is intended to extend, rather than extending into the dome-shaped area. In some cases, the ends of the spacer elements 50 may define the periphery of the domed area over which the membrane 15 is intended to extend. There may be several advantages to locating the spacer element 50 outside of or adjacent to the periphery of the dome-shaped region over which the membrane portion 151 is intended to extend. For example, by locating one or more spacer elements 50 outside of or adjacent to the dome-shaped area in which the flexible member is intended to extend, the spacer and membrane may be combined as described above. Any reduction to the intended stroke volume of the pump chamber 181 is minimized.

It should be understood that the spacer element 50 within the pump chamber, if present, can be arranged in any other suitable manner, for example as shown in FIG. 7. The left pump chamber 181 in FIG. 7 includes a spacer 50 arranged similarly to that of FIG. 6, but with only one break or passage 50a extending vertically through approximately the center of the pump chamber 181. Spacer 50 may be arranged to define a concave shape similar to that of FIG. 6 (i.e., the top of spacer 50 may form a semi-ellipse as shown in FIGS. 3 and 4). ), spherical, box-like shapes, etc., and may be arranged in other suitable ways. The right pump chamber 181 in FIG. 7 shows an embodiment in which the spacers 50 gas spacers 50 are arranged vertically and the gaps 50b between the spacers 50 are also arranged vertically. Similar to the left pump chamber, the spacer 50 in the right pump chamber 181 may define a recess of semi-elliptical, spherical, box-like or any other suitable shape. However, it should be understood that the spacer elements 50 can have a fixed height, a different spatial pattern than shown, etc.

Also, the membrane 15 itself can have gas spacer elements, or other features in addition to or in place of the spacer elements 50, such as ribs, ledges, tabs, grooves, channels, etc. These features in the membrane 15 may help prevent the membrane 15 from sticking, etc., and/or may help control how the sheet folds or otherwise deforms as it moves during the pumping operation. Other features may be provided to help. For example, a bulge or other feature in membrane 15 can help the sheet deform consistently and avoid folding in the same area during repeated cycles. Folding the membrane 15 in the same area in repeated cycles can cause the membrane 15 to fail prematurely in that crease area, and therefore the characteristics of the membrane 15 may control how and where the creases occur. can help you.

In this exemplary embodiment, base member 18 of cassette 24 defines a plurality of controllable valve features, fluid pathways, and other structures to guide movement of fluid within cassette 24. FIG. 6 shows a plan view of the pump chamber side of the base member 18, which can also be seen in the perspective view of FIG. FIG. 8 shows a perspective view of the back side of the base member 18. FIG. 9 shows a plan view of the back side of the base member 18. A tube 156 of each of ports 150 , 152 , and 154 is in fluid communication with a respective valve well or chamber 183 formed in base member 18 . The valve wells or chambers 183 are fluidly isolated from each other by walls surrounding each valve well or chamber 183 and by sealing the engagement of the membrane 15 with the walls around the well or chamber 183. Similarly, valve well 185 can be sealed from port 186 by manipulation of cassette membrane 15. The pump inlet or outlet valve has wells 189, 194 that can be sealed from ports 190, 192 by manipulation of the cassette membrane 15. As mentioned above, the membrane 15 is inserted into each valve well or chamber 183, 185, 189 and 194 (and other parts of the base member 18), for example by being pushed into contact with the walls when loaded into the cycler 14. may be sealingly engaged with the walls around the wall). Fluid within valve wells or chambers 183, 185, 189 and 194 will flow through each valve port or orifice 184, if membrane 15 is not pushed into sealing engagement with valve port or orifice 184, 186, 190 and 192; It can flow into or out of 186, 190 and 192. Accordingly, each valve port or orifice 184, 186, 190 and 192 is a valve (e.g. , “volcano valve”). The cassette valve port or orifice seat is defined by a raised wall 196 to form a valve seat (see FIG. 3) so that closure of the port by the cassette membrane 15 and associated valve control area of the gasket is more reliably achieved. can do. However, in other embodiments, if the cassette membrane 15 is sufficiently flexible or appropriately shaped and the applied pressure is sufficient to seal the valve ports 184, 186, 190 and 192 from the valves, The cassette valve port seat may not include raised walls 196.

As discussed in more detail below, cycler 14 can selectively control the position of portions of membrane 15, thereby controlling flow through various fluid channels and other paths within cassette 24. As such, valve ports (such as port 184) can be opened and closed. Flow through valve port 184 is to the rear side of base member 18. For the valve ports associated with heater bags and drains (ports 150 and 152), valve port 184 leads to a common channel 200 formed on the rear side of base member 18. Channel 200, like valve well 183 and chambers 183, 185, 189, 194, is separated from other channels and passageways of cassette 24 by seat 16 and in sealing contact with the walls of base member 18 forming channel 200. bring about. For the valve port 184 associated with the patient line port 154, flow through the port 184 leads to a common channel 202 on the rear side of the base member 18. Common channel 200 may also be referred to herein as an upper fluid bath, and common channel 202 may also be referred to as a lower fluid bath.

Returning to FIG. 6, each of the spikes 160 (shown uncapped in FIG. 6) is in fluid communication with a respective valve well 185, which has a wall and a membrane 15 between the walls forming the well 185. are separated from each other by a sealing engagement of the two. If the membrane 15 is not in sealing engagement with the ports 186, fluid within the valve wells 185 can flow into the respective valve ports 186. (Again, the position of the portion of membrane 15 above each valve port 186 can be controlled by cycler 14 to open and close valve ports 186.) Flow through valve ports 186 18 and into the common channel 202. Thus, according to one aspect of the invention, the cassette has multiple solution supply lines (or other lines providing substances for providing dialysate) connected to a common manifold or channel of the cassette. and each line can have a corresponding valve to control flow to and from the line to a common manifold or channel. Fluid within channel 202 can flow into lower opening 187 of pump chamber 181 by opening 188 leading to lower pump valve well 189 (see FIG. 6). If the respective portions of membrane 15 are not pressed into sealing engagement with the ports 190, flow from the lower pump valve wells 189 may pass through the respective lower pump valve ports 190. As shown in FIG. 9, lower pump valve port 190 opens into a channel that communicates with lower opening 187 of pump channel 181. Flow exiting pump chamber 181 may pass through top opening 191 and into a channel communicating with top valve port 192. Flow from the upper valve ports 192 (when the membrane 15 is not in sealing engagement with the ports 192) communicates within each upper valve well 194 and with a common channel 200 on the rear side of the base member 18. The opening 193 can be entered.

As will be appreciated, the cassette 24 is configured such that the pump chamber 181 can pump fluid to and from any of the ports 150, 152, and 154 and/or any of the spikes 160. can be controlled. For example, fresh dialysate provided by one of the containers 20 connected by line 30 to one of the spikes 160 can be supplied by opening the appropriate valve port 186 to the appropriate spike 160 (and if may be drawn into the common channel 202 by closing other valve ports 186 to other spikes. Also, the lower pump valve port 190 can be opened and the upper pump valve port 192 can be closed. Thereafter, a portion of the membrane 15 (i.e., pump diaphragm 151) associated with the pump chamber 181 is moved (e.g., away from the base member 18 and the pump chamber wall) so as to reduce the pressure within the pump chamber 181. fluid can be routed through the selected spike 160, through the corresponding valve port 186, into the common channel 181, through the opening 188 and into the lower pump valve well 189, through the (open) lower pump valve port. 190 and into the pump chamber 181 through the lower opening 187. Valve ports 186 are independently operable, allowing the option of drawing fluid through any one or combination of spikes 160 and associated source vessels 20 in any desired order or simultaneously. Of course, only one pump chamber 181 needs to be operated to draw fluid. Other pump chambers may remain inoperable and sealed to flow by closing the appropriate lower pump valve ports 190.

Fluid within pump chamber 181 allows lower pump valve port 190 to be closed and upper pump valve port 192 to be open. As the membrane 15 moves towards the base member 18, the pressure within the pumping chamber 181 may increase, causing fluid within the pumping chamber 181 to pass through the upper opening 191 and into the (open) upper Through pump valve port 192 into upper pump valve well 194 and through opening 193 into common channel 200 . By opening the appropriate valve port 184, fluid within the channel 200 can be directed to the heater bag port 150 and/or drain port 152 (and into the corresponding heater bag line or drain line). Thus, for example, fluid within one or more of the containers 20 can be drawn into the cassette 24 and pumped out to the heater bag 212 and/or drain.

Fluid within heater bag 22 (e.g., after being suitably heated on a heater tray for introduction into the patient's body) opens valve port 184 for heater bag port 150 and lowers pump valve port 190. and opening the upper pump valve port 192 into the cassette 24. By moving the portion of membrane 15 associated with pump chamber 181 away from base member 18 , the pressure within pump chamber 181 can be reduced, thereby directing fluid flow from heater bag 22 to pump chamber 181 . Go inside. With the pump chamber 181 filled with heated fluid from the heater bag 22, the upper pump valve port 192 can be closed and the lower pump valve port 190 can be opened. Valve port 184 for patient port 154 can be opened and valve port 186 for spike 160 can be closed to deliver heated dialysate to the patient. By moving the membrane within pump chamber 181 toward base member 18 , the pressure within pump chamber 181 can be increased, thereby causing fluid to flow through lower pump valve port 190 and through opening 188 . and flows into the common channel 202 to and through the (open) valve port 184 for the patient port 154. This operation can be repeated a suitable number of times to deliver the desired volume of heated dialysate to the patient.

When draining the patient, the valve port 184 for the patient port 154 can be opened, the upper pump valve port 192 can be closed, and the lower pump valve port 190 (with the spike valve port 186 closed) can be opened. ) can be opened. Membrane 15 can be moved to draw fluid from patient port 154 into pump chamber 181. Thereafter, the lower pump valve port 190 can be closed, the upper valve port 192 can be opened, and the valve port 184 for the drain port 152 can be opened. Fluid from pump chamber 181 can then be pumped into a drain line for disposal into a drain or collection container or for sampling. Alternatively, fluid may be routed to one or more spikes 160/lines 30 for sampling or drainage purposes. This operation can be repeated until sufficient dialysate has been removed from the patient and pumped into the drain.

Heater bag 22 can also serve as a mixing container. Depending on the predetermined treatment requirements for the individual patient, dialysate or other solutions with different compositions can be connected to the cassette 24 via suitable solution lines 30 and spikes 160. A measured amount of each solution can be added to heater bag 22 using cassette 24 and mixed according to one or more predetermined recipes stored in microprocessor memory and accessible to control system 16. Alternatively, a user may enter predetermined treatment parameters via user interface 144. The control system 16 can be programmed to calculate the appropriate mixing requirements based on the type of dialysate or solution container connected to the spike 160, and the control system 16 then Delivery of the formulated mixture can be controlled.

According to aspects of the invention, the pressure exerted by the pump on the dialysate being infused into or removed from the patient is a "pull" or "pull" resulting from pressure fluctuations during draining and filling operations. This can be controlled to minimize the patient's sensations. For example, when draining dialysate, the suction pressure (or vacuum/negative pressure) can be reduced near the end of the draining process, thereby minimizing patient sensation of dialysate removal. . A similar approach can be used when approaching the end of the filling operation, ie, the delivery pressure (or positive pressure) can be reduced near the end of the filling. Different pressure profiles can be used for different fill and/or drain cycles if the patient is found to be sensitive in nature to fluid movement during different cycles of treatment. For example, a relatively higher (or lower) pressure can be used during fill and/or drain cycles when the patient is asleep compared to when the patient is awake. The cycler 14 may, for example, use an infrared motion detector to infer that the patient is asleep if the patient's movement is reduced, or detect changes in blood pressure, brain waves, or other parameters indicative of sleep. , the patient's sleep/wake state can be detected. Alternatively, cycler 14 can simply "ask" the patient "Are you asleep?" and control system operation based on the patient's response (or lack of response).

Patient Line Status Detector In one aspect, the patient line status detector detects when a fluid line to a patient, such as patient line 34, is properly primed before being connected to the patient. Although fluid line condition detection is described with respect to a patient line, it is understood that aspects of the invention include detecting the presence of and/or the filling condition of any suitable tube segment or other conduit. It should be. Accordingly, aspects of the invention are not limited to use with patient lines, as any suitable conduit and tubular body detector may be used. In some embodiments, a fluid line condition detector can be used to detect proper priming of a tubing segment at a patient-connecting end of a fluid line. Patient line 34 can be connected to an indwelling catheter within a patient's blood vessels, within a body cavity, subcutaneously, or within another organ. In one embodiment, patient line 34 can be a component of peritoneal dialysis system 10 and delivers dialysate to and receives fluid from the patient's peritoneal cavity. The tube segment near the tip of the line can be placed in an upright position in a cradle in which the sensor element of the detector is located.

FIG. 10 shows a front perspective view of an exemplary configuration of a fluid line condition detector 1000 that is mounted or mounted on the left exterior side of the housing 82, e.g., on the left side of the front door 141. It can be exposed there in any way. For purposes of illustration, the fluid line status detector will be described as patient line status detector 1000. The patient line 34 should preferably be primed before being connected to the patient, as otherwise air may be delivered into the patient's body, increasing the risk of complications. It is. Depending on the configuration, it may be acceptable to have up to 1 mL of air in the patient line 34 before it is connected to the patient's peritoneal dialysis catheter. Exemplary configurations of patient line condition detectors 1000 described below generally meet or exceed this criterion because they detect fluid levels within properly positioned tubing segments of line 34. This is because, after priming, the air remaining at the tip of line 34 is at most about 0.2 mL.

In one aspect, a first configuration of patient line condition detector 1000 can include a base member 1002. There may also be a patient line status detector housing 1006 attached to (or generally molded together with) the base member 1002, such that the detector housing 1006 can extend outwardly from the base member 1002. . Detector housing 1006 defines a tube or connector retention channel 1012 within which tube segment 34a or its associated connector 36 near the distal end of patient line 34 may be placed. The portion of the detector housing 1006 facing the base member 1002 may be substantially hollow, resulting in an open cavity 1008 (shown in FIGS. 11 and 13) at the rear of the detector housing 1006. can do. Open cavity 1008 can accommodate placement and positioning of sensor elements (1026, 1028, 1030, and 1032 shown in FIG. 13) next to channel 1012 in which tube segment 34a can be placed. In alternative embodiments, there may also optionally be a stabilizing tab 1010 extending outwardly from the base member 1002. The stabilizing tab 1010 can have a concave outer shape so that it substantially conforms to the curvature of the patient line connector 36 when the patient line 34 is placed within the patient line condition detector housing 1006. can. Stabilizing tabs 1010 can help prevent connector 36 from shifting during priming of patient line 34, thereby improving the accuracy and efficiency of the priming process. Detector housing 1006 can have a shape that generally helps define a tube or connector retention channel 1012 that is further configured to accommodate the transition from tube segment 34a to tube connector 36. Can have varying dimensions.

In this exemplary embodiment, channel 1012 can substantially match the shape of patient line connector 36. As a result, channel 1012 may be "U-shaped" so as to encompass a portion of connector 36 when placed within channel 1012. Channel 1012 may be comprised of two separate features: a tube portion 1014 and a cradle 1016. In another aspect, tube portion 1014 can be positioned below cradle 1016. Additionally, a pair of side walls 1018 and a rear wall 1020 may form a cradle 1016. Both side walls 1018 can be slightly convex in shape, and the rear wall 1020 can be generally flat or otherwise have a contour that generally matches the shape of adjacent portions of the connector 36. be able to. The generally convex shape of sidewall 1018 helps lock patient line connector 36 in place when placed within cradle 1016.

In an exemplary embodiment for the first configuration of patient line status detector 1000, region 36a of patient line connector 36 is a generally planar surface that can be fixedly positioned relative to opposing rear wall 1020 of channel 1012. can have. Additionally, this region of the connector 36 can have a recess 37 on the opposite side, which is positioned adjacent the opposite sidewall 1018 of the channel 1012 when the connector 36 is positioned within the detector housing 1006. be able to. A recess 37 can be defined by a raised element 37a located on the side of the connector 36. One of these recesses 37 is partially visible in FIG. The two sidewalls 1018 can have a generally mating shape (eg, a convex shape, etc.) that engages the recess 37 and helps lock the connector 36 in place within the cradle 1016. This helps prevent inadvertent removal of connector 36 and tube segment 34a from detector housing 1006 during priming of patient line 34. If the raised elements 37a of the connector 36 are made from a sufficiently flexible material (such as polypropylene, polyethylene or other similar polymeric material), the threshold tensile force on the connector 36 Segment 34a can be released from detector housing 1006.

In another aspect, the tube portion 1014 of the cavity 1012 can surround a majority of the tube segment 34a just before the tube segment 34a is attached to the connector 36. Tube section 1014 can accommodate most of tube segment 34a using three structures: two side walls 1018 and a back wall 1020. In embodiments, the two side walls 1018 and the back wall 1020 allow light from the plurality of LEDs (such as LEDs 1028, 1030 and 1032 in FIG. 13) to be directed through the walls without being significantly obstructed or diffused. It can be transparent or sufficiently translucent (e.g., constructed from plexiglass) to allow for. An optical sensor 1026 (shown in FIG. 12) can also be placed along one of the walls 1018, which can detect the light being emitted by the LED. In the illustrated embodiment, a transparent or translucent plastic insert 1019 can be configured to snap into the main detector housing 1006 in the area where the LED is located within the housing.

FIG. 12 shows a perspective layout with LEDs 1028, 1030 and 1032 and optical sensor 1026 surface mounted on a patient line status detector printed circuit board 1022. FIG. 13 shows a top view of LEDs 1028, 1030, and 1032 and optical sensor 1026 mounted on a detector circuit board 1022, where the detector circuit board 1022 is mounted on the rear wall 1020 and side wall 1018 of the detector housing 1006. Can be placed adjacent to each other. FIG. 14 is an exploded perspective view of sensing assembly 1000 showing the relative position of printed circuit board 1022 and translucent or transparent plastic insert 1019 with respect to housing 1006.

Referring also to the exemplary embodiment of FIG. 11, a detector circuit board 1022 can be disposed over the support structure 1004 and an internal open cavity 1008, with the internal open cavity 1008 extending outwardly from the base member 1002. A detector housing 1006 is formed from the detector housing 1006. Base member 1002 and support structure 1004 can be attached to each other, or generally molded, such that base member 1002 is generally perpendicular to support structure 1004. This orientation generally allows the plane of detector circuit board 1022 to be generally perpendicular to the long axis of tube segment 34a when secured within channel 1012. Detector circuit board 1022 can generally match the cross-sectional shape of open cavity 1008 and include a cutout 1024 (FIG. 12) that generally matches the cross-sectional shape of channel 1012 formed by back wall 1020 and side wall 1018 (FIG. 10). , FIG. 13). A detector circuit board 1022 can then be placed within the open cavity 1008, and the cutout 1024 is inserted into the detector circuit board 1024 to ensure proper alignment of the detector circuit board 1022 with the tube segment 34a or connector 36. generally adjacent rear wall 1020 and side wall 1018 of container housing 1006.

Detector circuit board 1022 can include a plurality of LEDs and at least one optical sensor that can be attached to circuit board 1022; in one embodiment, the LEDs and optical sensor can be surface mounted to circuit board 1022. can. In one aspect, the detector circuit board 1022 can include a first LED 1028, a second LED 1030, a third LED 1032, and an optical sensor 1026. First LED 1028 and second LED 1030 may be positioned to direct light through the same sidewall 1018a of channel 1012. The light emitted by the first LED 1028 and the second LED 1030 can be directed in a generally parallel direction and generally perpendicular to the sidewall 1018a to which they are closest. Optical sensors 1026 may be positioned along opposing sidewalls 1018b of channel 1012. Additionally, a third LED 1032 can be placed along the back wall 1020 of the channel 1012. In this exemplary embodiment, this configuration of LED and optical sensor 1026 allows patient line condition detector 1000 to detect three different conditions during the process of priming patient line 34, i.e., tube segment 34a or connector 36. completely filled with fluid (primed condition), tube segment 34a or connector 36 not completely filled (unprimed condition), or tube segment 34a and/or connector 36 absent from channel 1012 ( Line absent state) can be detected.

For example, when used in a peritoneal dialysis system, such as peritoneal dialysis system 10, configuring detector circuit board 1022 in this manner allows appropriate control signals to be sent to PD cycler controller system 16. The controller system 16 may then notify the user via the user interface 144 to position the tip of the line 34 at the patient line condition detector 1000 before making the connection to the peritoneal dialysis catheter. can. The controller can then monitor the placement of tube segment 34a within patient line condition detector 1000. The controller then instructs priming of the line 34, instructs the end of priming when the line 34 is primed, and then instructs the user to remove the distal end of the line 34 from the patient line condition detector 1000. and can be instructed to disconnect and connect it to the user's peritoneal dialysis catheter.

Surface mounting LEDs 1028, 1030 and 1032 and optical sensor 1026 to circuit board 1022 can simplify the manufacturing process for the device and allow patient line status detector 1000 and circuit board 1022 to occupy relatively little space. 1012 and can help eliminate errors that may result from movement of the LEDs or optical sensors relative to each other or into the channel 1012. Without surface mounting of sensor components, misalignment of the components can occur during assembly of the device or during its use.

In one aspect, the optical axis (or central optical axis) of the LED 1032 can form an oblique angle with the optical axis of the optical sensor 1026. In the illustrated embodiment, the optical axes of first LED 1028, second LED 103, and optical sensor 1026 are each generally parallel to each other and to back wall 1020 of channel 1012. Accordingly, the amount of light directed from the LED to the optical sensor 1026 depends on (a) the presence or absence of a translucent or transparent conduit within the channel 1012, and/or (b) the conduit (which may be, for example, tube segment 34a). may vary depending on the presence of liquid within. Preferably, the LED 1032 is placed near the sidewall furthest from the optical sensor 1026 (e.g., 1018a) to refract a portion of the light emitted by the LED 1032 due to the presence of a translucent or transparent tube segment 34a within the channel 1012. can be placed. The degree of refraction away from or toward optical sensor 1026 may depend on the presence or absence of fluid in tube segment 34a.

In various embodiments, the oblique angle of the LED 1032 relative to the optical sensor 1026 creates a more robust system for determining the presence or absence of liquid with a translucent or transparent conduit in the channel 1012. LED 1032 can be positioned such that its optical axis can form any angle from 91° to 179° with the optical axis of optical sensor 1026. Preferably, the angle can be set within a range of about 95° to about 135° relative to the optical axis of the optical sensor. More preferably, the LED 1032 can be configured to have an optical axis of approximately 115°±5° relative to the optical axis of the optical sensor. In the exemplary embodiment shown in FIG. 13, the angle θ of the optical axis of LED 1032 with respect to the optical axis of optical sensor 1026 was set to approximately 115°±5°. (The optical axis of optical sensor 1026 in this particular embodiment is approximately parallel to back wall 1020 and approximately perpendicular to side wall 1018b.) The angle of LED 1032 with respect to the optical axis of optical sensor 1026 is An advantage of attaching the air-filled tube is to use an LED 1032 oriented at an angle of approximately 115°, and an LED with its optical axis oriented perpendicular or parallel to the optical axis of the optical sensor 1026. It was confirmed in a series of tests comparing the performance of optical sensor 1026 in distinguishing fluid-filled tube segments (wet tubes) from segments (dry tubes). The results showed that the angled LED-based system was more robust in identifying the presence or absence of liquid in tube segment 34a. By using the angled LED 1032, it was possible to select a signal strength threshold of the optical sensor, beyond which an empty tube segment 34a could be reliably detected. It was also possible to select an optical sensor signal strength threshold below which the fluid-filled tube segment 34a could be reliably detected.

FIG. 15 shows a graph of test results demonstrating that the patient line condition detector 1000 is capable of distinguishing between liquid-filled tube segments 34a (primed condition) and empty tube segments 34a (unprimed condition). The result is LED 1032 (third LED) oriented at an angle of approximately 115° to the optical axis of optical sensor 1026 and LED 1030 (second LED) oriented approximately parallel to the optical axis of optical sensor 1026. LED). The results plotted in FIG. 15 demonstrate that the patient line state detector 1000 can reliably distinguish between primed and unprimed states. If the relative signal strength associated with the light received from LED 1030 was approximately 0.4 or greater, then only the light signal received from LED 1032 was used to determine the upper signal detection threshold 1027 and lower limit for the unprimed versus primed state. The signal detection threshold 1029 could be determined. An upper threshold 1027 can be used to identify an unprimed state, and a lower threshold 1029 can be used to identify a primed state. Data points located above the upper threshold 1027 are associated with empty tube segment 34a (unprimed condition) and data points located below lower threshold 1029 are associated with liquid-filled tube segment 34a (primed condition). It will be done. The relatively narrow region 1031 between these two thresholds limits the range of relative signal intensities associated with light received from the LED 1032 over which the assessment of the priming status of the tube segment 34a may be uncertain. Define. A controller (e.g., control system 16, etc.) may be programmed to send an appropriate message to the user whenever the signal strength associated with the light received from the LED 1032 is within this uncertainty range. can. For example, a user may be instructed to evaluate whether tubing segment 34a and/or connector 36 are properly attached to patient line status detector 1000. In the context of a peritoneal dialysis system, if the optical sensor 1026 generates a signal corresponding to an empty tube segment 34a, the controller can instruct the cycler to continue priming the patient line 34 with dialysate. The controller may use the signal corresponding to the fluid-filled tube segment 34a to stop further priming and indicate to the user that the fluid line 34 is ready to be connected to the dialysis catheter. can.

In embodiments, the cycler 14 controller may continuously monitor the received signal from one of the LEDs at the beginning of the priming procedure. Upon detecting a change in the received signal, the controller can stop further fluid pumping in order to take a complete measurement using all of the LEDs. If the received signal is sufficiently within the range indicative of a wet tube, further priming can be stopped. However, if the received signal is within the uncertainty region 1031 or within the "dry" region, the cycler commands a series of small incremental pulses of fluid into the patient line by the pumping cassette, with each pulse of fluid After that, read the LED signal strength repeatedly. Priming can then be stopped as soon as a reading indicating a fluid fill line is achieved at the level of the sensor. Incremental pulses of fluid can be achieved by commanding short pulses of the valve to connect the pressure reservoir to the pump actuation chamber or control chamber. Alternatively, the controller commands the application of continuous pressure to the pump actuation chamber or control chamber, causing the outlet valve of the pump to open and close briefly to produce a series of fluid pulses. can be commanded.

FIG. 16 shows a graph of test results demonstrating the superiority of an angled LED 1032 (LEDc) when compared to an LED whose optical axis is approximately perpendicular to the optical axis of the optical sensor 1026 (LEDd). In this case, the relative signal strength generated by optical sensor 1026 in response to light from the LED was plotted against the signal strength associated with the light from the LED. Although some separation between liquid-filled (“primed”) and empty (“unprimed”) tube segments 34a was evident at an LED relative signal strength of approximately 0.015; There remained a substantial number of "unprimed" data points 1035 that could not be distinguished from "primed" data points based on this threshold. On the other hand, the relative signal strength 1033 associated with the light from LEDc between 0.028 and 0.03 is between the "primed" tube segment 34a (primed condition) and the "unprimed" tube segment 34a (unprimed condition). can be effectively identified. Therefore, angled LEDs (1032) can produce more reliable data than LEDs oriented at right angles.

In another embodiment, patient line status detector 1000 can also determine whether tube segment 34a is present in channel 1012. In one aspect, first LED 1028 and second LED 1030 can be placed next to each other. One LED (eg, LED 1028) may be positioned such that its optical axis passes approximately through the center of a suitably positioned translucent or transparent conduit or tube segment 34a within channel 1012. A second LED (eg, LED 1030) can be positioned such that its optical axis is slightly shifted off-center with respect to conduit or tube segment 34a within channel 1012. Thus, by pairing the LEDs on/off center on one side of the channel 1012, with the optical sensor 1026 on the opposite side of the channel 1012, a liquid conduit or tube segment 34a is inserted into the channel 1012. It was found that the reliability of determining whether a is present or absent is improved. In a series of tests in which tube segment 34a was alternately absent, present but not properly positioned, or present and properly positioned within channel 1012, the first LED and the second LED were detected by optical sensor 1026. Signal measurements were taken from two LEDs 1030. The signals received from each LED are plotted against each other and the results are shown in FIG.

As shown in FIG. 17, in most cases when tube segment 34a was absent from channel 1012 (region 1039), the signal strength received by optical sensor 1026 due to LEDa (LEDa received strength) is It was found that the signal strength was not significantly different from the signal strength received from the LEDa during the calibration step lit in the known absence of any tube in channel 1012. Similarly, the signal strength associated with LEDb (LEDb received strength) was found not to be significantly different from LEDb during the calibration step when LEDb was illuminated in the known absence of any tube in channel 1012. Patient line condition detector 1000 can reliably determine that there is no tubing in channel 1012 if the ratio of LEDa to its calibrated value and the ratio of LEDb to its calibrated value are each approximately 1±20%. can. In a preferred embodiment, the threshold ratio may be set to 1±15%. In embodiments where patient line status detector 1000 is used with a peritoneal dialysis cycler, the values of LEDa and LEDb in region 1039 of FIG. 17 can be used to indicate, for example, the absence of tube segment 34a in channel 1012. . The cycler controller is configured to notify the user via the user interface 144 that further pumping operations are paused and that the distal end of the patient line 34 within the patient line status detector 1000 is required to be properly positioned. Can be programmed.

The configuration and alignment of the three LEDs and optical sensor 1026 described above can generate the necessary data using translucent or transparent fluid conduits (eg, tube segment 34a) with a wide range of translucency. In further testing, patient line condition detector 1000 uses samples of tubing with significantly different degrees of translucency to distinguish liquid from air within a fluid conduit, or to identify the presence or absence of a fluid conduit. It was found that it is possible to provide reliable data for It was also able to provide reliable data as to whether the PVC tubing used was non-sterile or sterile (eg sterilized with EtOX).

In certain embodiments, fluid conduit or patient line 34 may be transparent or translucent to the first spectrum or spectra of light. The fluid conduit may also be opaque to light of the second spectrum or spectra. The LEDs used in patient line condition detector 1000 may be selected based on the light transmission characteristics of the fluid conduit. For example, the first LED may be selected to emit light in a first spectrum or at least one of a plurality of first spectra. The second LED may be selected to emit light in a second spectrum or spectra. For example, the fluid conduit may be transparent or translucent to at least light in the infrared spectrum, but opaque to at least light in the ultraviolet spectrum. The first LED (eg, LED 1030) can emit light in the infrared spectrum, while the second LED (eg, LED 1028) can be selected to emit light in the ultraviolet spectrum. Optical sensor 1026 can sense the light emitted from each LED, or multiple sensors can be included in optical sensor 1026, one for each LED wavelength. A filter or the like may be included as part of the optical sensor 1026 to filter out undesirable wavelengths of light. For example, trim (shortpass and longpass) and bandpass filters can be used.

In embodiments where LED 1028 emits ultraviolet light and LED 1030 emits infrared light, optical sensor 1026 may sense light from both LEDs 1028, 1030 when no tube is in channel 1012. If a tube (eg, patient line 34) is installed in channel 1012, light from ultraviolet LED 1028 may be blocked by the presence of the tube. Light from the infrared LED can be recorded by optical sensor 1026 because the tube can be translucent or transparent to its light spectrum. Accordingly, the control system 16 determines that when the intensity of light from the ultraviolet LED 1028 is below a predefined threshold (which may be set to indicate that the light is completely or nearly completely obscured), the intensity of the light from the infrared emitting LED 1030 A tube can be declared present if the light exceeds at least a certain threshold. This may be further beneficial because the patient line condition detector 1000 may be able to distinguish between tubes of expected type or composition and undesired or unauthorized tube types. Patient line condition detector 1000 may also have greater robustness in distinguishing between various scenarios. For example, the use of ultraviolet and infrared LEDs may assist the patient line condition detector 1000 in determining whether a foreign object or detritus is present in place of an improperly placed tube. Accordingly, troubleshooting and prompts generated for display on the user interface may be streamlined and cycler 14 may provide a better patient experience. This may be particularly desirable when patients are setting up their usual care, as they are getting ready for bed each night and prolonged troubleshooting can result in lost sleep and frustration.

In some embodiments, one of the LEDs 1028, 1030 used for tube detection may be omitted by matching the light source to the characteristics of the tube. Infrared emitting LEDs 1030 may be omitted, and control system 16 only monitors light from ultraviolet emitting LEDs that are blocked (e.g., decreases below some predefined threshold) to indicate that a tube is present or channel 1012 can determine whether it is properly installed.

Measurements taken by optical sensor 1026 from LEDs 1028, 1030, 1032 may be used as input to a patient line condition detector algorithm to detect the condition of tube segment 34a. In addition to detecting a filled tube segment 34a, an empty tube segment 34a, or an absent tube segment 34a, the results of the algorithm can be indeterminate and, in some cases, detect tube segments in the patient line status detector 1000. Indicating movement or improper positioning of segment 34a, or possibly the presence of a foreign object within channel 1012 of patient line condition detector 1000. Due to manufacturing variations, the output from the LEDs 1028, 1030, 1032 and the sensitivity of the optical sensor 1026 can vary between different assemblies. Therefore, it may be advantageous to perform an initial calibration of the patient line condition detector 1000. For example, the following procedure can be used to obtain calibration values for the LEDs and sensors.

(1) Ensure that tube segment 34a is not loaded into patient line status detector 1000.
(2) Query the optical sensor 1026 regarding the following four different states. (a) LED not lit (b) First LED 1028 (LEDa) lit (c) Second LED 1030 (LEDb) lit (d) Third LED 1032 (LEDc) lit (3) "LED not lit" signal value Subtract from each of the other signal values to determine their environmental correction values and store these three measurements as "no tube" calibration values.

Once calibration values for the LEDs and sensors are obtained, the condition of tube segment 34a can be detected. In this exemplary embodiment, the patient line condition detector algorithm performs condition detection in the test as follows:
(1) Inquire about the following four different states of the optical sensor 1026. (a) No LED (b) First LED 1028 (LEDa) lit (c) Second LED 1030 (LEDb) lit (d) Third LED 1032 (LEDc) lit (2) Change the "LED not lit" value to another Subtract from each of the values to determine their environmental correction values.
(3) Calculate relative LED values by dividing the test values associated with each LED by their corresponding calibration ("no tube") values.

result:
- If the environmentally corrected LEDa value is less than 0.10, there may be a foreign object in the detector or an indeterminate result may be reported to the user.
- Report to the user that no tube segment is present in the detector if the environmentally corrected LEDa and LEDb values are within ±15% of their respective stored calibration (no tube) values.
- If the environmentally corrected LEDb value is approximately 40% or more of its stored calibration (no tube) value, (a) check the signal associated with LEDc, and (i) determine whether the environmentally corrected signal associated with LEDc is (ii) if the environmental correction signal associated with LEDc is greater than or equal to approximately 150% of its calibration ("no tube") value, it reports to the user that the tube segment is empty; ) below approximately 125% of the value, then report to the user that the tube segment is filled with liquid; (iii) otherwise the result is indeterminate and the measurement should be repeated (e.g. tube segments that may be moving, may be uneven, or are unclear, or the tube segment should be checked to ensure that it is properly inserted into the detector. Report this to the user.
- If the environmentally corrected LEDb value is less than about 40% of its stored calibration ("no tube") value, the LEDc threshold for determining the presence of a dry tube can be larger. In one embodiment, for example, the LEDc empty tube threshold has been empirically found to follow the following relationship ([LEDc empty tube threshold] = -3.75 x [LEDb value] + 3).

Once it is determined that the tube segment 34a is loaded into the patient line condition detector 1000, the patient line condition detector algorithm may do the following. a) Inquire of the optical sensor 1026 whether the LED is not lit or not, and store this as the no-LED value. b) Turn on LEDc. c) Query the optical sensor 1026, subtract the no-LED value from the LEDc value, and store this as the initial value. d) Start pumping. e) Interrogate the optical sensor 1026 and subtract the no-LED value from the next LEDc value. f) If this value is less than 75% of the initial value, conclude that the tube segment 34a is filled with liquid, reduce pumping, check the detector status using the procedure described above, and Sometimes, it reports to the user that priming is complete. If not, continue repeating the queries, calculations and comparisons. In one embodiment, the system controller can be programmed to perform the interrogation protocol as often as desired, such as every 0.005 to 0.01 seconds. In embodiments, the entire query cycle may conveniently occur every 0.5 seconds.

Figure 18 shows the results of the sample calibration procedure for six cycles. It is noted that the signal strength range that distinguishes dry from wet tubes (the "wet/dry threshold" range) changes between different cycles. (Variations in these ranges may be due to slight variations in the manufacturing, assembly, and positioning of the various components.) Therefore, during calibration, for each cycler, the dry A wet/dry threshold signal intensity range can be assigned that optimally separates the data points generated by the tube.

In some examples, the threshold at which control system 16 can register a wet or liquid-filled tube may be different. For example, in some embodiments, as shown in FIG. 19, the threshold value may depend on a value previously collected when tube segment 34a was determined to be dry. This may help the patient line condition detector 1000 more reliably determine when a transition from dry line to prime line occurs. Additionally, this may help make patient line condition detector 1000 more resistant to drift that may occur after repeated use and over time.

FIG. 19 shows a flowchart 1050 detailing several actions that may be performed to prime a fluid line. As shown, at block 1052, the user may turn on the cycler 14 and begin preparing for treatment. If the patient line status detector 1000 is not empty at block 1054, the control system 16 of the cycler 14 may enter a troubleshooting mode at block 1056. During troubleshooting, control system 16 of cycler 14 generates one or more messages or alerts for display on the user interface of cycler 14 suggesting actions the user can take to resolve the problem. It is possible. A user may be requested to remove old lines, clean patient line condition detector 1000, or check for detritus, for example. If the patient line status detector 1000 is empty at block 1054, the user may load a patient line into the patient line status detector 1000 at block 1058. Cycler 14 may display a prompt instructing the user to do so. Control system 16 may use patient line status detector 1000 to determine whether patient line status detector 1000 is empty, as described elsewhere herein.

Control system 16 of cycler 14 may coordinate collection of condition readings on patient line 34 using patient line condition detector 1000 at block 1060 . To collect this reading, control system 16 can, for example, turn on LED c 1032 and check the light intensity using optical sensor 1026. If the reading indicates that the patient line is not dry at block 1062, the control system 16 of the cycler 14 may proceed to troubleshooting at block 1056. During troubleshooting, control system 16 of cycler 14 may display one or more messages, alerts, or warnings for display on the user interface of cycler 14 suggesting actions the user can take to resolve the problem. can be generated. For example, the user may be asked to delete and reload a line. If patient line status detector 1000 continues to determine that a wet line is present, treatment on set 12 may be inhibited. The user may be requested to discard the set 12 and restart with a new set 12. Various guidance graphics may be generated for display on a user interface during troubleshooting.

If the ratio of the reading to the "no tube" calibration value matches a predefined range or threshold, the reading may be determined to indicate that the line is dry. At block 1062, if the reading indicates that the line is dry, control system 16 may check the characteristics of the reading against one or more criteria. For example, in the embodiment shown in FIG. 19, control system 16 may check whether the ratio of the reading to the "no tube" value is greater than a threshold (eg, 1.7). Control system 16 can also check whether the ratio is the maximum seen for that patient line. If the reading (or ratio) is the highest ever in a block, it can be saved as the maximum value in block 1068. Alternatively, if the reading (or ratio) is less than or equal to a threshold (eg, 1.7), the maximum value may be stored as the threshold value at block 1068.

In some embodiments, control system 16 may require multiple readings (e.g., consecutive readings) indicating that the patient line is dry before instructing cycler 14 to prime the patient line. . At block 1070, if the predefined number of checks have not been completed, control system 16 may return to block 1060 to collect another reading. At block 1070, if the precondition number of checks is completed, control system 16 of cycler 14 may calculate a primed patient line threshold at block 1072. In alternative embodiments, this primed tube threshold may be calculated at a different point in time, eg, after the first reading at block 1060. In such embodiments, the primed tube threshold may be updated on each subsequent pass through block 1060.

As shown in FIG. 19, the primed line threshold can be based on the maximum value stored at block 1068. In certain embodiments, the primed tube threshold may be calculated as the greater of a predefined value (eg, 1.7) and the output of a predefined equation. For example, an equation using a constant added to the percentage of the maximum value from block 1068 can be used. In a particular embodiment, the equation may be Primed Tube Threshold = 1.1 + (Max Dry Tube [from block 1068] * 0.2).

At block 1074, control system 16 of cycler 14 may command cycler 14 to pump fluid through patient line 34. At block 1076, control system 16 of cycler 14 may command readings collected at patient line condition detector 1000. At block 1078, if the reading indicates that the primed tube threshold has not been breached, the control system 16 of the cycler 14 may return to block 1074 and command additional pumping. Alternatively, readings can be collected while pumping is occurring. If the reading indicates that the primed tube threshold has been breached at block 1078, the control system 16 of the cycler 14 may declare the line primed at block 1080. The control system 16 of the cycler 14 also provides a prompt to the user (e.g., via a screen or prompt generated on the user interface) to instruct the user to proceed to the next step in the treatment setup at block 1080. Communication can be coordinated. A reading may be determined to indicate that the threshold has been breached when the ratio of the reading to the “no tube” value is greater than the primed tube threshold calculated at block 1072.

In some embodiments, control system 16 of cycler 14 may limit the volume of fluid that is allowed to be replaced during priming of patient line 34. For example, there may be a volume threshold (e.g., the line volume at the nominal patient line 34) imposed on the volume displaced to prime the patient line 24, and the control system 16 Notifications or alerts can be generated when The user may be instructed (via the GUI) to check the line to ensure that it is not fully primed and properly attached to the patient line status detector 1000. Control system 16 of cycler 14 may allow cycler 14 to return to block 1074 and may continue priming upon receiving user input that the line is properly seated and not fully primed. In some embodiments, there may be an upper limit on the number of times that continuous pumping may be allowed. When this upper limit is reached or exceeded, the control system 16 of the cycler 14 can trigger an alert or error and prevent the cycler 14 from performing therapy on its set 12.

FIG. 20 shows a perspective view of a second configuration of patient line condition detector 1000. Two or more different patient line status detector configurations may be required to accommodate different types of patient line connectors. In this exemplary embodiment, the second configuration of patient line status detector 1000 may include substantially the same components as the first configuration of patient line status detector 1000. However, to accommodate different types of connectors, the second configuration can include a raised element 1036 above the housing 1006 rather than the stabilizing tab 1010 found in the patient line condition detector 1000 of the first configuration. . Raised element 1036 can generally conform to the shape of a standard patient line connector cap or connector flange.

According to aspects of the present disclosure, detector housing 1006 may not include tube portion 1014. Accordingly, the open cavity 1008 is arranged to allow for the placement of the detector circuit board 1022 so that the LED and optical sensor can be placed next to the translucent or transparent patient line connector 36 instead of being part of the tube. can do. Accordingly, channel 1012 can be differently shaped to accommodate the transmission of LED light through connector 36.

In some embodiments, the fluid line detector 1000 is not used to detect the priming status of a segment of tubing, but simply uses one or more LEDs in the fluid line detector 1000. The presence of line segments can be detected. The presence and proper placement of line segments can be determined using fewer LEDs than the embodiments described above.

In other embodiments, other types of sensors may be used to detect one or more conditions of interest associated with a fluid line, such as fluid line 30 or patient line 34. For example, fluid line detector 1000 can include a physically actuated switch such as an electrical or magnetic contact switch or a microswitch. Activation of such a switch allows fluid line detector 1000 to detect the presence of fluid line connector 36 or tube segment 34a. In some embodiments, more than one such switch can be used in fluid line detector 1000. This can provide some redundancy or can be used to detect that multiple line segments of interest are properly placed. In embodiments, for example, a microswitch can be placed in channel 1012 to be activated when tube segment 34a is installed within channel 1012. Alternatively or additionally, a microswitch can be placed within the cradle 1016, for example, to be activated when the fluid line connector 36 is placed on the fluid line detector 1000. In such embodiments, the cycler controller (e.g., control system 16) operates until all of the one or more switches indicate that the line and/or connector is properly installed within the fluid line detector 1000. May not allow priming of the tube.

In another embodiment, fluid line detector 1000 can detect the presence and condition of tube segments using a split ring resonator-based sensor. Such a detector is shown, for example, in U.S. patent application Ser. The content of the application is Incorporated herein by reference.

In some embodiments, the sensor of fluid line detector 1000 detects the type of fluid line 34 installed in fluid line detector 1000 (e.g., adult size vs. pediatric size, opaque vs. translucent, etc.) It can be configured as follows. Fluid line connector 36 and/or tube segment 34a may have different identifying characteristics (eg, different geometries) depending, for example, on the type of line being used. The sensors of fluid line detector 1000 can be configured to recognize what type of line is present based on sensing the presence or absence of such identifying features.

For example, if fluid line detector 1000 is configured to use a microswitch, the switch may be configured to detect the presence of a particular type of fluid line connector 36. Fluid line connectors 36 in each type of line can include different features (eg, different protrusions or voids, or differently arranged protrusions or voids). When installed in the fluid line detector 1000, the fluid line connector 36 may actuate a predetermined switch or groups of switches to detect the presence of a particular type of fluid line connector 36. If an invalid or unexpected combination of switches is actuated, or if a combination of switches is actuated that does not correspond to the fluid line configuration intended for use with the cycler or medical device, the user may receive an incompatible or The controller can be programmed to post the appropriate line. This arrangement of switches can also be used to detect improperly installed lines or connectors.

In other embodiments, priming of the fluid line 34 with a liquid is completed by detecting when the liquid flow is replaced by air flow within the lumen of the distal end of the line 34 or within the connector 36 at the distal end of the line 34. can be inferred. The difference in resistance to flow between air and liquid within a lumen of a given inner diameter is determined by monitoring the flow rate of the liquid when subjected to a given force (by gravity or by active pumping). can be detected. The inner diameter of the lumen can be selected to optimize discrimination between air and liquid flow. In most cases, this involves introducing a flow restriction near or at the end of the fluid line 34 or tip connector. A suitably selected flow restriction at the tip of line 34 or connector 36 allows relatively unrestricted air flow out of line 34 and is sufficient to slow the progression of the liquid column through line 34. Liquid flow is obstructed. This increase in liquid flow resistance or change in pressure drop across the restriction zone can be determined by using a flow meter in the liquid flow path or by measuring the change in liquid volume in the upstream pump chamber over a predetermined time interval. , can be detected. In embodiments where a membrane-based positive displacement pump is used, the pressure within the working chamber of the pump is monitored (e.g., by applying Boyle's law or other pressure-volume relationship for an ideal gas in an enclosed space). By this, the rate of change of the liquid volume in the pump chamber can be calculated, and the pressure in the working chamber is indicative of the pressure in the pump chamber of the pump. A controller that receives liquid flow data from a fluid line or calculates liquid flow exiting the pump chamber by measuring pressure changes within the pump chamber can compare the liquid flow to a predetermined value. Alternatively, the controller can calculate the drop in liquid flow rate, compare the change in flow rate to predictive knowledge, and declare that the fluid line has been primed with liquid.

Zones where flow is impeded can include constrictions, obstructions, partial occlusions or restrictions (e.g., orifices) that allow the easy passage of air but prevent the passage of liquids such as dialysate. impede passage. The feature may include a short segment of the distal tube or fluid connector 36 that includes a region having a cross-sectional area that is less than the cross-sectional area of the fluid conduit at the proximal section of the fluid line. As used herein, "restriction" is intended to include any feature that differentiates between air and liquid in a fluid conduit to increase resistance to flow.

In embodiments, the restriction may be removable from the tip of the fluid line or associated connector. For example, the restriction can be included in a plug or cap that remains in place on the fluid line 34 during priming of the fluid line 34. The restriction can, for example, be molded as part of the closure or cap during manufacture. This restriction may be a recess, void, channel or other flow path in the stopper portion of the cap. The plug portion of the cap can be inserted directly into the fluid conduit or into the lumen of the attached connector 36. Alternatively, the plug portion of the plug or cap can be sized to have a diameter that is smaller than the diameter of the fluid conduit or associated connector lumen. When the cap is installed, the bung portion occludes a portion of the fluid conduit, creating a small gap between the outer surface of the bung and the inner wall of the conduit, thereby creating a restriction.

When pumping fluid to prime fluid line 34, the fluid moves at a relatively high flow rate as air is freely displaced out of fluid line 34 through the restriction. The increase in impedance when the liquid reaches the restriction results in a slower flow rate. The flow rate can be monitored by a controller receiving input from one or more sensors as priming occurs. As the flow rate decreases, air is forced out of the line past the restriction, and it can be inferred that a given applied force is now trying to force the liquid through the restriction. In some embodiments, the controller may employ additional logic to identify multiple possible causes for reduced liquid flow in the fluid line.

In embodiments where the restriction is an orifice (located at the tip of a fluid line or within an attached connector), the cross-sectional area of the orifice opening is selected to produce the desired amount of impedance to liquid flow. can do. Furthermore, the selected pumping pressure can be selected such that the flow rate when pumping air and the flow rate when pumping liquid are detectably different.

It may be desirable to place the restriction slightly upstream of where the fluid line 34 is fully primed. This allows some liquid to flow through the restriction during the determination or recognition period when the controller is determining whether the impedance to liquid flow has changed. Having line volume downstream from the restriction provides a fluid buffer to accommodate additional fluid while the controller makes priming decisions and shuts down the fluid pump, thus reducing the amount of fluid exiting the tip of the fluid line. Helps prevent overflow. Preferably, the delay characteristics of the pumping system in response to changes in liquid flow impedance are determined empirically for the system once the system parameters are selected. These parameters may include, for example, the force or pressure exerted by the pump, the frequency of pumped volume determination or flow measurement, the internal diameter and length of the tubing, the characteristics of the flow restriction, and the response time of the controller and pump. . Once the system characteristics are determined, the restricted tube or connector buffer volume required to prevent overflow can be determined empirically. For illustrative purposes, if the flow rate through the restriction is 30 mL/min, and it takes about 5 seconds for the controller and pump to recognize and respond to an impedance change, then while the system is responding to an impedance change, , a hysteresis fluid volume of approximately 2.5 mL is moved. In such embodiments, the downstream volume beyond the restriction can be set to approximately 2.5 mL, or slightly more than 2.5 mL. This serves to help minimize the amount of air remaining in the fluid line 34 during priming without overpriming the line and allowing fluid to overflow the line and leak out. be able to.

Alternatively, the restriction can extend along the line axis a distance that allows the restricted flow path volume to approach the expected flow rate while the impedance change is being detected. This embodiment may be desirable if the restriction is included within the fluid line cap.

In some embodiments, a material that is air permeable but substantially liquid impermeable can be used to restrict liquid flow. Such materials allow relatively unrestricted passage of air, but can restrict or prevent the passage of liquid. This material can be placed at the end of the fluid line 34 to allow air to be pumped out of the line 34, but prevent overflow and spillage when the line 34 reaches a primed condition. can. Then, for example, when a user uncappers the line, the material can be removed along with the fluid line cap. In some specific embodiments, the material used can be Goretex or another similar material (eg, a breathable material that can be either microporous or macroporous). As mentioned above, a decrease in the flow rate as the liquid reaches the material signals that the fluid line 34 has reached a prime condition.

21 and 22 illustrate exemplary embodiments of fluid line cap 5320, fluid line 34 and fluid line connector 36. FIG. As shown, a restriction 5322 is included within fluid line 34. In other examples, the cap 5320 can have interior features that incorporate a restriction similar to the illustrated restriction 5322. In this example, restriction 5322 is optionally positioned such that there is some fluid line 34 volume downstream of restriction 5322. The restriction 5322 in the example embodiment is a portion of the fluid path that has a reduced cross-sectional area. In other examples, restriction 5322 can be an orifice or membrane that has one or more pores cut out, perforated, or otherwise increases resistance to the passage of liquid.

As shown in FIG. 21, liquid 5324 within fluid line 34 has not yet reached restriction 5322. At this point, the flow rate of fluid (eg, stratified columns of air and liquid) through fluid line 34 may be relatively high. Once the air column is exhausted, liquid 5324 within fluid line 34 will reach restriction 5322. At this point, the flow rate decreases due to the change in impedance. When the cycler determines that the impedance has changed, some liquid 5324 continues to flow. Once detected, the cycler can be programmed to stop the flow of liquid through the line. At this point, as shown in FIG. 22, liquid 5324 has substantially primed the entire line 34, including the line 34 volume downstream of restriction 5322. The controller can be programmed to notify the user that line 34 is primed and ready to connect to a catheter or other device for treatment.

23 and 24 illustrate another embodiment of a fluid line 34, fluid line connector 36, and fluid line cap 5320. As shown, there are no restrictions on fluid line 34 or fluid line connector 36. Fluid line cap 5320 acts as a plug for fluid line 34 and includes a restriction 5322. In example embodiments, the restriction 5322 can include a notch, groove, or channel recessed around the bung portion of the fluid line cap 5320. Restriction 5322 is sized such that it allows air to be pumped out of the line with relatively little resistance during priming, but impedes liquid flow once the air column is fully discharged. It can be done. Once the controller determines that line 34 is primed, it can then instruct the user to remove line cap 5320 and attach fluid line connector 36 to an indwelling catheter or other similar device. .

As shown in FIG. 23, liquid 5324 within fluid line 34 has not yet reached restriction 5322. At this point, the flow rate of fluid (gas plus liquid) through fluid line 34 may be relatively high. When the liquid 5324 in the fluid line 34 reaches the restriction 5322, the flow rate decreases due to the impedance change between the gas flow and the liquid flow through the restriction 5322. When the controller determines that the impedance has changed, some liquid 5324 continues to flow. Once detected, the controller stops the flow of liquid 5324 through the line. At this point, liquid 5324 has substantially primed the entire line 34, as shown in FIG. The controller can then notify the user that line 34 has been primed and line cap 5320 can be removed. When the cap 5320 is removed, any excess liquid 5324 that has been pumped can fill the volume of the fluid line 34 previously occupied by the plug portion of the fluid line cap 5320. Alternatively, the controller can be programmed to receive a signal from the user that the cap 5320 has been removed, prompting the cycler or pump to advance a small amount of liquid down the liquid line 34 for use. The controller can be programmed to previously add to the tip of line 34 or connector 36.

FIG. 25 shows a representative example of a fluid line cap 5320 with a bung or bung portion 5500. As shown, the fluid line cap 5320 includes a plug portion 5500 that may be sized to protrude and fit snugly within the fluid conduit of the fluid line 34. A notch is provided within the bung portion 5500 of the fluid line cap 5320, which serves to create a restriction 5322 when the fluid line cap 5320 is installed on the end of the fluid line 34 or line connector 36. In the figure, the notch is substantially triangular in cross-section. In other embodiments, any suitable cross-sectional shape may be used. Other configurations can be used, such as, for example, a narrow lumen through the length of the plug 5500, which is otherwise solid. Also, as shown in FIG. 25, the end of the plug portion 5500 that extends into the fluid flow path can optionally be rounded (or tapered). This may facilitate placement of fluid line cap 5320 over fluid line 34.

FIG. 26 shows another embodiment of a fluid line cap 5320. Similar to FIG. 25, the fluid line cap 5320 includes a plug portion 5500 that may be sized to protrude and fit snugly within the fluid conduit of the fluid line 34. Restriction 5322 in FIG. 26 is a flow path that allows fluid to flow from the fluid conduit of fluid line 34 through the interior of bung portion 5500 and into the interior volume of fluid line connector 36. FIG. 27 shows a cross-sectional view of an example fluid line cap 5320 in a longitudinal plane. The cross-sectional area of the flow path is smaller than the cross-sectional area of the fluid line 34 fluid conduit.

FIG. 28 shows another embodiment of a fluid line cap 5320 installed on fluid line connector 36 of fluid line 34. FIG. As shown in FIG. 29, cross-sectionally at line 28-28 in FIG. 28, fluid line connector 36 includes a segment that extends into the fluid conduit of fluid line 34. As shown in FIG. The tubing of fluid line 34 may be secured (eg, glued, bonded, welded, etc.) to fluid line connector 36. Fluid line connector 36 includes a flow path from a fluid conduit of fluid line 34 to a connector fitting 5502 included as part of fluid line connector 36 . Connector fitting 5502 mates with cooperating features of a complementary connector (e.g., of a patient's indwelling catheter) to allow fluid to be delivered from the site (e.g., the peritoneal cavity or another body cavity) and/or It can be made possible to be drawn out. Although a Luer lock is shown in the example embodiment, any of numerous other suitable connectors or fittings may be used.

The cap in the example embodiment includes a stopper portion 5500. Bung portion 5500 is sized to extend into the fluid path of fluid line connector 36. In example embodiments, the diameter of plug portion 5500 is smaller than the diameter of the flow path within fluid line connector 36. When the plug portion 5500 of the fluid line cap 5320 is installed within the flow path of the fluid line connector 36, a small gap remains between the outer surface of the plug portion 5500 and the inner wall of the flow path. The plug portion 5500 therefore serves to reduce the cross-sectional area of the flow path, creating a restriction 5322.

As mentioned above, in some embodiments, a small gap between the outer surface of the plug portion 5500 and the inner wall of the channel does not need to exist. Alternatively, the plug portion 5500 can fit snugly into the flow path. The outer surface of the bung portion 5500 may be recessed with a notch to reduce the cross-sectional area of the flow path and create a restriction, or the bung portion inserted into the connector lumen may be solid. may include a narrow flow path to create a restricted flow path.

In one aspect, a change in flow path impedance can be determined based on an ongoing flow rate estimate of a pumping stroke from the pump cassette. Further, the stroke volume estimate can be used to distinguish between a change in flow rate due to an empty pump chamber and a change in flow rate due to liquid 5324 reaching restriction 5322 in fluid line 34 . Estimation of flow rate and stroke volume during the course of a pumping stroke is discussed further below.

In some embodiments, a controller algorithm that estimates stroke volume can be used to stop the stroke before all chambers are delivered to the fluid line. That is, the controller can be programmed to instruct the pump to perform a partial delivery stroke during priming to avoid reaching the end of the pump diaphragm gas stroke. This can help ensure that any reduction in flow rate is not due to the pump diaphragm reaching the rigid pump chamber wall at the end of the pump stroke. When the controller determines that the volume of fluid pumped per unit time has decreased by more than a predetermined threshold, it can be assumed that the liquid 5324 in the fluid line 34 has reached the restriction 5322 and the line is It can be considered as primed.

In other embodiments, the controller can direct the pump to pump fluid until a discontinuity in flow rate is detected. Once a discontinuity is detected, the controller can instruct the pumping device (eg, a cycler) to attempt to deliver a small amount of fluid from another pump chamber of the dual pump cassette. If the flow discontinuity is due to reaching the end of the pump diaphragm gas stroke, then the flow from the other chambers should be greater than the end flow rate from the first chamber. If the discontinuity is due to a primed line condition, the flow rate from the other chambers will be similar to the ending flow rate from the first chamber. Therefore, the device controller can determine that the line has been primed.

In some embodiments, a nominal internal tube volume for fluid line 34 may be determined. The controller then directs the pump to move fluid down line 34 until the volume of fluid primed down line 34 is within one chamber volume of the nominal tube volume. be able to. Once the remaining volume in line 34 is determined to be less than the volume of a full pump stroke, the controller may register the next flow discontinuity as indicative of a primed condition.

The nominal internal volume of line 34 can be determined based on the type of set being used. For example, a pediatric set may have a smaller internal tube volume than an adult set. In some embodiments, the device controller can determine this information via optical sensors. In some embodiments, the set can include a bar code or data matrix that can be read by a camera on the pumping device or cycler, and the encoded information allows the controller to determine the type of set installed. can do. A controller that receives input from a camera may also be able to detect different features or geometries of the part of the set. For example, fluid line connector 36 can have a unique detectable geometry that is detectable by fluid line detector 1000 as described above. Alternatively, the user may manually enter information regarding the type of tubing or pump cassette in use at the pumping device's user interface.

Line Priming Line Priming To reduce the time required to prime a line, it is preferred that the pumping device actively prime the line rather than allowing gravity-based flow to accomplish the work. There are cases. In weight-based priming, which is a standard procedure, fluid flow through the line is determined by the head height of the reservoir in which the priming fluid is stored. The flow rate of fluid through the line during priming increases as the head height of the priming fluid reservoir increases. Actively priming the line by using one or more pumps allows the pumping device or cycler to simulate different head heights relative to the reservoir while the reservoir remains in a fixed position. If the fluid pump includes a pneumatically driven pump chamber, the amount of air pressure applied to the pump chamber through the membrane allows the flow rate to be controlled to the desired value without repositioning the priming reservoir. Eliminating the need to relocate fluid reservoirs helps keep the pumping or dialysis system compact, reduces the setup burden on the user, and allows for relatively fast priming of fluid lines.

In some embodiments where the channels and chambers of the pump cassette are to be primed with fluid, priming can occur in two or more stages. The first stage may prime the line (eg, with lower pump pressure or with passive gravity flow) at a lower effective head height than the second or subsequent stage. Turbulent flow at relatively high flow rates can result in air bubbles or pockets being introduced or trapped in various locations or recesses of the pump cassette. This problem can be alleviated by allowing the pump cassette to be primed slowly and then proceeding to a more rapid priming process once the fluid reaches the fluid line downstream of the cassette. The length of the first stage can be predetermined empirically through testing or by measuring the amount of fluid volume transferred from the priming reservoir to the cassette or attached fluid line.

Reducing air bubble formation or entrapment is desirable for multiple reasons, including the ability of line priming sensors to detect air bubbles and direct the controller to stop the process and issue a user alert.

The duration of the first priming phase may depend on the type of cassette used (number of pumps and valves, complexity of flow paths) and the volume of its internal fluid path and pump chamber. Preferably, the priming is such that the fluid is able to displace air from the cassette from the bottom to the top, and that most or all of the enclosed air is forced into the attached fluid line and then removed from the atmosphere. This is done at a flow rate slow enough to ensure that it is released into the air.

FIG. 30 shows a flowchart detailing several steps in which a controller can be used to control priming of a cassette and attached lines using two stages. In the example, the line being primed is a patient line extending from the pump cassette to the patient. The illustrated steps can be easily generalized to priming other fluid lines. As shown, in step 5570, the cycler begins priming the patient line by gravity feeding fluid into the line through the cassette. In example embodiments, the priming reservoir is a heater bag. Free flow can be achieved by controlling the valves of the cassette to create an open flow path between the patient line and the heater bag.

Upon initiating the priming operation in step 5570, the controller may start a timer for the first priming phase. The duration of the first priming phase can be determined empirically through testing to be sufficient to ensure that any air within the cassette has flowed out of the cassette and into the patient line. Using the example cassette shown in Figure 3, this duration can range from 1 second to 3 seconds. In one embodiment, the timer can be set to about 1.6 seconds. In control system embodiments that do not use a timer, but rather use a transition from the first priming stage when a predetermined volume of fluid is delivered from the priming reservoir, the predetermined volume is , which can be approximately 1 ml to 3 ml.

When the timer expires (or the predetermined volume has been delivered), the pumping device or cycler can proceed to step 5572 and begin actively priming the line. Preferably, step 5572 primes the line with a faster flow rate than step 5570. The cycler can continue to actively prime the patient line until the priming sensor indicates that the line has reached a fully primed condition. In some embodiments, the controller may then notify the user in the user interface that priming is complete and the primed line is ready to be connected.

Set Loading and Operation FIG. 31 (37) shows a perspective view of the APD system 10 of FIG. exposed (in this embodiment, door 141 is attached to cycler housing 82 by a hinge at the bottom of door 141). When loading the set 12, the cassette 24 is placed in the mounting position 145 with the membrane 15 and the pump chamber side of the cassette 24 facing upward, and the portion of the membrane 15 associated with the pump chamber and valve port is located at the door 141. can interact with control surface 148 of cycler 14 when closed. Attachment location 145 may be shaped to match the shape of base member 18, thereby ensuring proper orientation of cassette 24 at attachment location 145. In this exemplary embodiment, the cassette 24 and mounting location 145 have a large radius that requires the user to place the cassette 24 in the mounting location 145 in the proper orientation or the door 141 does not close. It has a generally rectangular shape with a single corner. However, it should be understood that other shape or orientation features for cassette 24 and/or mounting location 145 are also possible.

According to aspects of the invention, when cassette 24 is placed in mounting position 145, patient line 34, drain line 28 and heater bag line 26 are routed to the left through channel 40 of door 141 as shown in FIG. be done. Channel 40, which may include guides 41 or other features, may hold patient line 34, drainage line 28, and heater bag line 26 such that occluder 147 selectively routes the lines for flow. Can be opened and closed. When door 141 is closed, occluder 147 can force one or more of patient line 34 , drain line 28 , and heater bag line 26 against occluder stop 29 . In general, occluder 147 can allow flow through lines 34, 28, and 26 when cycler 14 is operating (and operating properly), but when cycler 14 is powered down. (and/or not operating properly), the line can be occluded. Closing the line can be done by pushing on the line or pinching the line to close the flow path in the line. Preferably, occluder 147 is capable of selectively occluding at least patient line 34 and drain line 28.

When the cassette 24 is installed and the door 141 is closed, the pump chamber side of the cassette 24 and the membrane 15 are compressed, e.g. by an air bladder, a spring, or by compressing the cassette 24 between the mounting location 145 and the control surface 148. Other suitable configurations of the door 141 behind the mounting location 145 can be pressed into contact with the control surface 148. By housing cassette 24 in this manner, membranes 15 and 16 can be pressed into contact with the walls and other features of base member 18, thereby allowing the channels of cassette 24 and Isolate other flow paths. The control surface 148 can include a flexible gasket or membrane, such as a piece of silicone rubber, or other material associated with the membrane 15, to selectively move a portion of the membrane 15 into the pump chamber. The pumping action of 181 and the opening and closing of the valve ports of cassette 24 can be effected. The control surface 148 can be associated with different portions of the membrane 15 and, for example, can be arranged in close contact with each other, such that portions of the membrane 15 are sensitive to the movement of corresponding portions of the control surface 148. Move accordingly. For example, membrane 15 and control surface 148 can be placed in close proximity to each other, and a suitable vacuum (or low pressure relative to the surroundings) can be introduced through a vacuum port suitably placed on control surface 148 to and a control surface 148 such that the membrane 15 and control surface 148 can be maintained between the membrane 15 and the control surface 148 to open or close the valve port and/or at least to the area of the membrane 15 that requires movement to effect the pumping action. are essentially pasted together. In another embodiment, membrane 15 and control surface 148 can be adhered to each other or otherwise suitably associated.

In some embodiments, the surface of the control surface 148 or gasket that faces the corresponding cassette membrane overlying the pump chamber and/or valve is textured or roughened. The texturing provides a plurality of small passages horizontally or tangentially along the surface of the gasket as the gasket is pulled against the surface of the corresponding cassette membrane. Thereby, exhaust can be promoted between the gasket surface and the cassette membrane surface at the textured position. It also allows for the determination of pump chamber volume using pressure-volume relationships (such as in the FMS procedure described elsewhere) by minimizing trapped pockets of air between the gasket and membrane. It is also possible to improve accuracy. It can also facilitate the detection of any liquid that may leak into the possible space between the gasket and the cassette membrane. In embodiments, this can be achieved by masking parts of the gasket type that do not form parts of the gasket that correspond to the positions of the pump membrane and valve leaflets. The non-masked portions of the gasket mold can then be subjected to a chemical engraving process, such as the Mold-Tech® texturing and chemical engraving process. Texturing can also be accomplished by any of a number of other processes, such as sandblasting, laser etching, or by using a mold making process using electrical discharge machining.

FIG. 32 shows a top view of the control gasket 148 of the cycler 14 that interacts with the pump chamber side of the cassette 24 (eg, shown in FIG. 6) to cause fluid pumping and flow path control within the cassette 24. Control gasket 148, which may include a sheet of silicone rubber, may be generally flat when stopped. Valve control region 1481 may (or may not) be defined in control gasket 148, for example by scoring, grooves, ribs or other features in or on the seat surface, and generally It may be arranged to be movable or elastically deformable/stretchable in a direction transverse to the plane. By moving inwardly/outwardly, the valve control region 1481 moves the relevant portion of the membrane 15 on the cassette 24 to control the respective valve ports 184 , 186 , 190 and 192 of the cassette 24 and thereby the cassette 24 . Control sulfur can be opened and closed. The two larger regions, pump control region 1482, may likewise be movable to move the associated molded portion 151 of membrane 15 cooperating with pump chamber 181. Similar to the shaped portion 151 of the membrane 15, the pump control region 1482 may be shaped to correspond to the shape of the pump chamber 181 as the control region 1482 extends into the pump chamber 181. In this manner, the portion of the control sheet or gasket 148 in the pump control region 1482 does not necessarily need to be stretched or resiliently deformed during the pumping operation.

Typically, control gasket 148 is constructed from a single material so that it can be easily formed from a mold. The flat portion of gasket 148 serves to compress and seal the cassette membrane 15 against the boundary or peripheral wall of the cassette, and when the cassette 24 is pressed against the control surface/gasket 148 and its supporting mating block, the cassette The liquid flow path within 24 is sealed. Similarly, when cassette 24 is pressed against control surface/gasket 148, fluid control ports 173A, 173C can be sealed to each other such that control chambers 171A, 2746 can be individually and Can be independently pressurized.

Alternatively, the movable portions of control gasket 148, such as pump control region 1482 and valve control region 1481, may include a material that has a different thickness, elasticity, and/or durometer value than the flat portions of gasket 148. The different materials can be fused together in a molding or overmolding operation, solvent bonded together, or attached using adhesives. Pump control region 1482 and valve control region 1482 of gasket 148 preferably operate in their appropriate positions in response to positive or negative actuation pressure to move the associated pump and valve portions of cassette membrane 15 a predetermined amount. Constructed of a thick and elastic elastomeric material that allows movement.

Each of regions 1481 and 1482 can have an associated vacuum or evacuation port 1483 that can be used, for example, to remove the cassette 24 after it has been loaded into the cycler 14 and the door 141 has been closed. All or substantially all of the air or other fluid that may be present between the membrane 15 and the control surface 148 of the cycler 14 may be removed. This helps to ensure intimate contact of the membrane 15 with the control regions 1481 and 1482 and helps to control the delivery of the desired volume by pumping and/or open/closed states of the various valve ports. be able to. Vacuum port 1482 is formed in a location where control surface 148 is not forced into contact with a wall or other relatively rigid feature of cassette 24. For example, in accordance with one aspect of the invention, one or both of the pump chambers of the cassette may include a vacuum vent gap region formed adjacent to the pump chamber. In this exemplary embodiment, as shown in FIGS. 3 and 6, the base member 18 includes a vacuum vent port gap or expansion feature 182 (e.g., a recessed region fluidly connected to the pump chamber) such that a vacuum vent port 1483 for the pump control region 1482 can be unobstructed from between the membrane 15 and the control surface 148 (e.g., through the membrane 15) any air or fluid can be removed. The expansion mechanism can also be located within the outer periphery of the pump chamber 181. However, by arranging the ventilation port mechanism 182 outside the outer periphery of the pump chamber 181, more of the pump chamber volume can be secured for pumping liquid, and, for example, the maximum footprint of the pump chamber 181 can be Can be used to pump dialysate. Preferably, the expansion mechanism 182 is located in a vertically downward position with respect to the pump chamber 181 so that any liquid leaking between the membrane 15 and the control surface 148 is directed to the vacuum port 1483 as soon as possible. drawn out through. Similarly, vacuum port 1483 associated with valve 1481 is preferably positioned vertically downward relative to valve 1481.

33A-C show that the control gasket 148 is optionally constructed or shaped to have a rounded transition between the base element 1480 of the control gasket 148 and the actuating portions of its valve and pump control regions 1481, 1482. Show that it can be done. These junctions or channels 1491 and 1492. A small radius can be formed for the transition from the base element 1480 to the valve control area 1481 and pump control area 1482, respectively. Rounded or smooth transitions may help prevent premature fatigue and failure of the material containing control gasket 148 and improve its life. In an optional embodiment, radial channel 1484 leads from vacuum port 1483 to pump control region 1482 and valve control region 1481 and may need to be somewhat longer to accommodate transition functions. Junctions or channels 1491 and 1492 act as vacuum channels to direct vacuum applied through the pressure delivery block between pump control region 1482 and valve control region 1481 and the corresponding pump and valve portions of cassette membrane 15. communicate and distribute into the potential space of. If necessary, these vacuum channels can optionally be used to directly fill the potential space between the gasket control area and the corresponding cassette membrane area to help separate the cassette from the pressure delivery block. It can also transmit pressure. Exemplary vacuum channels 1491 and 1492 run around or around the pump control region 1482 or valve control region 1481 of gasket 148 and help enable more uniform application of vacuum.

Although not required, these vacuum channels 1491 and 1492 can optionally extend circumferentially around the pump and valve control areas of gasket 148, as shown, for example, in FIGS. 33A-C. For either pump control region 1482 or valve control region 1481 of gasket 148, channels 1484 corresponding to a particular control region connect nearby gasket vacuum ports 1483 to channels 1491 that extend around the perimeter of its associated gasket control region. or 1492. Although the vacuum channels 1491, 1492 do not need to completely surround the associated pump or valve control area to ensure uniform application of vacuum across the surface of the control area, the circumferential arrangement may It also serves the purpose of providing a flexible mechanical transition between the base element 1480 of 148 and the body of the gasket control region 1481 or 1482.

Control areas 1481 and 1482 can be moved by controlling air pressure and/or volume on the opposite side of control surface 148 of cassette 24, for example on the back of the rubber sheet forming control surface 148. For example, as shown in FIGS. 34-35, the back side of the control surface 148 includes a control chamber or recess 171A located in relation to each control region 1481, 1482 and a control chamber or recess 171A located in relation to each control region 1482 and mutually A mating or pressure delivery block 170 can be disposed abuttingly including a control chamber or recess 171B that is isolated from (or at least can be controlled independently of each other if desired). The surface of the mating or pressure delivery block 170 forms a mating interface with the cassette 24 when the cassette 24 is pressed into operative association with the control surface 148 on which the mating block 170 abuts the rear surface. Thus, the control chambers or recesses of mating block 170 are coupled to complementary valves or popping chambers of cassette 24 and control regions 1481 and 1482 of control surface 148 adjacent mating block 170 and adjacent cassette 24 The relevant regions of the membrane 15 (molded portion 151, etc.) are sandwiched. Air or other control fluid can move in and out of control chambers or recesses 171A, 171B of mating block 170 relative to regions 1481, 1482, thereby moving control regions 1481 and 1482 as desired. Then, the valve port of the cassette 24 is opened and closed, and/or the pumping action in the pump chamber 181 is performed. In the embodiment shown in FIGS. 34-35, the control chamber 171A may be arranged as a cylindrical region or recess lining each of the valve control regions 1481 of the gasket 148. In one configuration of the valve control region 1481 of the gasket 148 (see, eg, FIGS. 33A-C), the surface of the valve control region 1481 is slightly higher than the entire surface of the gasket 148 and has an elastically deformable control region. bias toward the corresponding valve seat of cassette 24. Thus, positive air pressure applied to valve control region 1481 is biased toward sealing membrane 15 of cassette 24 against the valve seat. On the other hand, at least a portion of the negative pressure applied to the valve control region 1481 to lift the adjacent cassette membrane 15 off the valve seat may be spent to overcome the biased valve control region 1481 of the control gasket 148. Additionally, when the gasket 148 is positioned against the underlying mating block 170, the space 1478 under the dome of the control region 1481 joins the control chamber 171A, directing the control region 1481 toward the valve seat of the cassette 24. It is also clear that there will be a total control volume that is positively or negatively pressurized to move it towards or away from it. The amount of total control volume that needs to be pressurized will vary based on the shape and configuration of the valve control region 1481 of the gasket (eg, convex vs. concave toward the cassette 24).

The control chamber or recess 171B can include an ellipsoidal, oval, or hemispherical cavity or recess that abuts the back side of the pump control region 1482. A fluid control port 173A may be provided for each control chamber 171A, allowing the cycler 14 to control the fluid volume and/or fluid pressure in each of the valve control chambers 1481. A fluid control port 173C may be provided for each control chamber 171B, allowing cycler 14 to control the volume of fluid and/or pressure of fluid in each of volume control chambers 1482. For example, mating block 170 may include various ports, channels, openings, voids, and/or other features that communicate with control chamber 171 to allow suitable air pressure/vacuum to be applied to control chamber 171. The manifold 172 can be mated with the manifold 172 . Although not shown, air pressure/vacuum control may be accomplished in any suitable manner through the use of controllable valves, pumps, pressure sensors, accumulators, and the like. Of course, the control areas 1481, 1482 can be controlled by gravity-based systems, hydraulic systems and/or mechanical systems (such as by linear motors), or by pneumatic systems, hydraulic systems, gravity-based systems and mechanical systems. It should be understood that the movement can be accomplished in other ways, such as by a combination of systems that include.

FIG. 36 shows the assembly and disassembly of an integrated pressure distribution module or assembly 2700 suitable for use in a fluid flow control device operating a pump cassette and as a pressure distribution manifold 172 and mating block 170 of a cycler 14. Show the diagram. FIG. 94 shows a control including a pneumatic manifold or block, a port for supply pressure, a pneumatic control valve, a pressure sensor, a pressure delivery or mating block, and a region with a flexible membrane to actuate the pump and valves on the pump cassette. Figure 27 shows a diagram of an integrated module 2700 with a surface or actuator. The integrated module 2700 may also include a reference chamber within the pneumatic manifold for the FMS volumetric process to determine the volume of fluid present within the pump chamber of the pump cassette. The integrated module can also include a vacuum port and a set of passageways or channels from the interface between the actuator and the flexible pump and leaflets of the pump cassette to the fluid trap and liquid detection system. In some embodiments, the pneumatic manifold can be formed as a single block. In other embodiments, a pneumatic manifold can be formed from two or more manifold blocks that are fitted together, with gaskets disposed between the manifold blocks. The integrated module 2700 occupies relatively little space in a fluid flow control device and eliminates the use of tubing or flexible conduits connecting manifold ports to corresponding ports on a pressure delivery module or block that fits into a pump cassette. . Among other possible advantages, the integrated module 2700 reduces the size and assembly cost of the pneumatic actuation assembly of a peritoneal dialysis cycler, allowing the cycler to be smaller and less expensive. In addition, the short distance between the pressure or vacuum distribution ports on the pressure distribution manifold block and the corresponding pressure or vacuum delivery ports on the mating pressure delivery block, combined with the stiffness of the conduits connecting the ports, makes the installed The responsiveness of the pump cassette and the accuracy of the cassette pump volume measurement process can be improved. When used in a peritoneal dialysis cycler 14, in embodiments, an integrated module with a metal pressure distribution manifold that fits directly into a metal pressure delivery block also provides a Temperature differences can also be reduced, thereby improving the accuracy of the pump volume measurement process.

An exploded view of the integrated module 2700 is presented in FIG. An actuator surface or control gasket 148 attached to the mating block or pressure delivery block moves back and forth to pump fluid and/or open and close valves by pushing or pulling against the membrane 15 of the pump cassette 24. It includes a flexible region arranged as follows. For cycler 14, control gasket 148 is driven by positive and negative air pressure supplied to control volumes 171A, 171B behind control regions 1481, 1482. Control gasket 148 is attached to pressure delivery block or mating block 170 by a snug fit over raised surface 2744 on the front of mating block 170 by lip 2742 . Mating block 170 includes one or more surface indentations 2746 that align with and support the oval curved shape of one or more corresponding pump control surfaces 1482 to form pump control chambers. Can be done. Similar configurations, with or without surface indentations, may be included in forming the valve control area 171A to align with the corresponding control surface 1481 to control one or more valves of the pump cassette. Can be done. The mating block 170 includes grooves 2748 in the surface of the recess 2746 of the mating block 170 rearward of the pump control surface 1482 to facilitate flow of control fluid or gas from the port 173C to the rear overall pump control surface 1482. It can further include: Alternatively, rather than having grooves 2748, depressions 2746 can be formed with a roughened or tangentially porous surface.

In one embodiment, the inner wall of control chamber 171B includes a raised element (somewhat similar to spacer element 50 of pump chamber 181), for example as shown in FIG. 34 associated with pump control region 1482. be able to. These raised elements can take the form of plateau features, ribs, or other protrusions that set the control port back from the fully retracted control area 1482. This arrangement allows for a more even distribution of pressure or vacuum within the control chamber 171B and may prevent premature blocking of the control port by the control gasket 148. When the preformed control gasket 148 (at least in the pump control area) is fully extended either against the inner wall of the pump chamber of the cassette 24 during the delivery stroke or against the inside of the control chamber 171 during the fill stroke shall not be subjected to significant stretching forces. Thus, control region 1482 may extend asymmetrically into control chamber 171B such that control region 1482 may prematurely close one or more ports of the control chamber before the chamber is fully evacuated. Having features on the inner surface of the control chamber 171B that prevent contact between the control region 1482 and the control port may help ensure that the control region 1482 can uniformly contact the control chamber walls during the fill stroke. .

Mating block 170 connects pressure distribution manifold 172 to control surface 148 and delivers pressure or vacuum to various control areas of control surface 148. The mating block 170 also provides pneumatic conduits that supply pressure and vacuum to the valve control region 1481 and pump control region 1482, and to the connection from the vacuum port 1483 and pump control volume 171B to the pressure sensor. In this sense, it can also be called a pressure delivery block. Port 173A connects control volume 171A to pressure distribution manifold 172. Port 173C connects pump control volume 171B to pressure distribution manifold 172. Vacuum port 1483 is connected to pressure distribution manifold 172 via port 173B. In one embodiment, port 173B extends above the surface of pressure distribution block 170 past control surface 148 and at port 1483 without pulling control surface 148 over port 173B and interrupting flow. Provide vacuum.

Pressure delivery block 170 is attached to the surface of pressure distribution manifold 172. Ports 173A, 173B, 173C are aligned with the pneumatic circuit of pressure distribution manifold 172, which connects to valve port 2714. In one example, pressure delivery block 170 mates with pressure distribution manifold 172 with front flat gasket 2703 tightened therebetween. Block 170 and manifold 172 are held together mechanically, in embodiments, by using bolts 2736 or other types of fasteners. In another example, a high compliance element is placed or molded into either the pressure delivery block 170 or the pressure distribution manifold 172 rather than the flat gasket 2703. Alternatively, pressure delivery block 170 can be joined to pressure distribution manifold 172 by adhesive, double-sided tape, friction welding, laser welding, or other joining methods. Blocks and manifolds 172 can be formed from metal or plastic, and depending on the material, the method of joining will vary.

As shown in FIG. 38, the pressure distribution manifold 172 includes ports for pneumatic valves 2710, reference chambers 174, fluid traps 1722 and pneumatic circuits, or pressure reservoirs, integrated module 2700 connections that provide pneumatic connections between the valves. and includes a port 2714 for receiving a plurality of cartridge valves 2710. Cartridge valve 2710 includes, but is not limited to, binary valve 2660 that controls flow to valve control volume 171A, binary valves X1A, X1B, X2, X3 that control flow to pump control volume 171B, and air bladders 2630, 2640. , 2650 and binary valves 2661-2667 that control flow to pressure reservoirs 2610, 2620. Cartridge valve 2710 is pushed into valve port 2714 and electrically connected to hardware interface 310 via circuit board 2712.

The pneumatic circuit in pressure distribution manifold 172 includes grooves or slots 1721 on the front and back sides and approximately vertical holes connecting groove 1721 on one side to valve port 2714, fluid trap 1722, and to grooves and ports on the opposite side. It can be formed in combination with Some grooves 1721 can be directly connected to reference chamber 174. A single vertical hole can connect groove 1721 to multiple closely spaced and staggered valve ports 174. When grooves 1721 are separated from each other, in one example, by a front flat gasket 2703 as shown in FIG. 36, a sealed pneumatic conduit is formed.

The presence of liquid within fluid trap 1722 can be detected by a pair of conductive probes 2732. Conductive probe 2732 slides through back gasket 2704, back plate 2730, and hole 2750 before entering fluid trap 1722 of pressure distribution manifold 172.

The back plate 2730 seals the reference volume 174, the groove 1721 in the back of the pressure distribution manifold 172, and provides ports for the pressure sensor 2740 and pressure and vacuum lines 2734 and vents to the atmosphere 2732. . In one example, the pressure sensors can be IC chips that are soldered to a single substrate 2740 and pressed together against the back gasket 2704 of the back plate 2730. In one example, bolts 2736 tighten back plate 2730, pressure distribution manifold 172, and pressure delivery block 170, with gaskets 2703, 2702 therebetween. In another example, a back plate 2730 can be joined to the pressure delivery manifold 172, as described above. FIG. 95 presents the assembled monolithic module 2700.

FIG. 38 presents a schematic diagram of the pneumatic circuitry within the integrated manifold 2700 and the pneumatic elements outside the manifold. Pump 2600 generates vacuum and pressure. Pump 2600 is connected to vent 2680 and negative pressure or vacuum reservoir 2610 and positive pressure reservoir 2620 through three-way valves 2664 and 2665. The pressure within positive pressure reservoir 2620 and negative pressure reservoir 2610 is measured by pressure sensors 2678, 2676, respectively. Hardware interface 310 controls the speed of pump 2600 and the position of three-way valves 2664, 2665, 2666 to control the pressure in each reservoir. Self-connecting stripper element bladder 2630 is connected to either positive pressure line 2622 or negative pressure or vacuum line 2612 via a three-way valve 2661. Automation computer 300 commands the position of valve 2661 to control the position of stripper element 1461. Occluder bladder 2640 and piston bladder 2650 are connected to either pressure line 2622 or vent 2680 via three-way valves 2662 and 2663. Automation computer 300 commands valve 2663 to connect piston bladder 2650 to pressure line 2622 after door 141 is closed to ensure engagement of cassette 24 against control surface 148 . Occluder bladder 2640 is connected to pressure line 2622 via valve 2662 and restriction 2682. Occluder bladder 2640 is connected to vent 2680 via valve 2662. Orifice 2682 advantageously delays filling of occluder bladder 2640 retracting occluder 147 to maintain pressure within pressure line 2622. High pressure in pressure line 2622 maintains various valve control surfaces 171A and piston bladder 2650 driven against cassette 24, blocking flow to and from the patient when occluder 147 opens. Conversely, the n-connection from occluder bladder 2640 to vent 2680 is not restricted, so occluder 147 can be closed quickly.

Valve control surface 1481 is controlled by the pressure within valve control volume 171A, which is controlled by the position of three-way valve 2660. Valves 2660 can be individually controlled via commands from automation computer 300 sent to hardware interface 310. The valves that control the pumping pressure within the pump control volume 171B are controlled by two-way valves X1A and X1B. Valves X1A, X1B, in one example, can be controlled by hardware interface 310 to reach a pressure commanded by automation computer 300. The pressure within each pump control chamber 171B is measured by a sensor 2672. The pressure within the reference chamber is measured by sensor 2670. Two-way valves X2, X3 connect reference chamber 174 to pump control chamber 171B and vent hole 2680, respectively.

Fluid trap 1722 is present to vacuum line 2612 during operation, as described elsewhere herein. Fluid trap 1722 is connected to a port of pressure delivery block 170 by several lines. The pressure within fluid trap 1722 is monitored by pressure sensor 2674 attached to back plate 2730.

At the end of treatment, vacuum port 1483 can be employed to separate membrane 15 from control surface 148 before or while opening the door. Vacuum provided to vacuum port 1483 by a negative pressure source sealingly engages membrane 15 against control surface 148 during treatment. In some cases, even if the application of vacuum is intermittent, a substantial amount is required to prevent the door 141 from freely rotating to the open position and separate the control surface from the cassette membrane 15. power may be required. Accordingly, in embodiments, pressure distribution module 2700 is configured to provide a valved channel between a source of positive pressure and vacuum port 1483. Providing positive pressure at vacuum port 1483 can help separate membrane 15 from control surface 148, thereby allowing cassette 24 to be more easily separated from control surface 148 and opening door 141. Can be opened freely. Pneumatic valves in the cycler can be controlled by automation computer 300 to provide positive pressure to vacuum port 1483. Manifold 172 may include separate valved channels dedicated for this purpose, or alternatively may employ existing channel configurations and valves that are operated in a particular order.

In one example, positive pressure can be provided to vacuum port 1483 by temporarily connecting vacuum port 1483 to positive pressure reservoir 2620 . Vacuum port 1483 is typically connected to vacuum reservoir 2610 through a common fluid connection chamber or fluid trap 1722 in manifold 172 during treatment. In one example, the controller or automation computer can simultaneously open valve X1B between the positive pressure reservoir and volume control chamber 171B and valve X1A between the negative pressure reservoir and the same volume control chamber 171B; This pressurizes the air within fluid trap 1722 and vacuum port 1483. Pressurized air flows between membrane 15 and control surface 148 through vacuum port 1483, breaking any vacuum bond between the membrane and control surface. However, in the illustrated manifold, the stripper element 1491 of the cap stripper 149 can expand while positive pressure is provided to the common fluid collection chamber 1722 fluid, which means that the stripper bladder 2630 is in the vacuum supply line 2612. This is because it is connected to. In this example, in a subsequent step, the fluid trap 1722 can be regulated off from the newly pressurized vacuum line by a valve, and two valves connecting the positive pressure reservoir and the vacuum reservoir to the volume control chamber 171B. X1A, X1B can be closed. Vacuum pump 2600 is then operated to reduce the pressure within vacuum reservoir 2610 and vacuum supply line 2612, thereby allowing stripper element 1491 to be retracted. Door 141 can then be opened after removing cassette 24 from control surface 148 and retracting stripper element 1491.

According to aspects of the present disclosure, vacuum port 1483 can be used to detect leaks in membrane 15, and a liquid sensor in a conduit or chamber connected to vacuum port 1483 can be used to detect leaks in membrane 15. Liquid can be detected if the liquid is present or otherwise introduced between the membrane 15 and the control gasket 148. For example, vacuum port 1483 can be aligned with and sealingly associated with complementary vacuum port 173B in mating block 170, thereby making complementary vacuum port 173B a common may be sealingly associated with a fluid passageway 1721 leading to a fluid collection chamber 1722 of the . Fluid collection chamber 1722 can include an inlet through which vacuum can be applied and distributed to all vacuum ports 1483 of control surface 148. By applying a vacuum to the fluid collection chamber 1722, fluid can be drawn from each of the vacuum ports 173B and 1483, thus removing fluid from any space between the membrane 15 and the control surface 148 in the various control areas. be done. However, if liquid is present in one or more of the regions, the associated vacuum port 1483 can draw liquid into the vacuum port 173B and into the line 1721 leading to the fluid collection chamber 1722. Any such liquid may collect in fluid collection chamber 1722 and be detected by one or more suitable sensors, such as a pair of conductivity sensors that detect a change in conductivity within chamber 1722 indicative of the presence of liquid. . In this embodiment, the sensor can be placed on the bottom side of the fluid collection chamber 1722 and the vacuum source connects to the chamber 1722 at the top of the chamber 1722. Thus, when liquid is drawn into the fluid collection chamber 1722, the liquid can be detected before the liquid level reaches the vacuum source. Optionally, a hydrophobic filter, valve or other component can be placed at the vacuum source connection to chamber 1722 to help further resist liquid entry into the vacuum source. In this way, the controller 16 detects and acts on a liquid leak (e.g., issues a warning, closes the liquid inlet valve, etc.) before the vacuum source valve is placed at risk of contamination by liquid. the pumping operation).

In the example schematic shown in FIG. 38, a calibration port 2684 is shown. Calibration port 2684 can be used to calibrate various pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 in the pneumatic system. For example, a pressure reference can be connected to the cycler's pneumatic circuit via calibration port 2684. With the pressure reference connected, the valves in the pneumatic system can be actuated to connect all of the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 to the same fluid volume. The pressure reference can then be used to establish a known pressure in the pneumatic system. The pressure measurements from each of the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 can be compared to the known pressure of the pressure reference, and the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 can be adjusted accordingly. Can be calibrated. In some embodiments, selected pressure sensors of pressure sensors 2672, 2674, 2676, 2677, 2678 are connected to and brought to a reference pressure for group or individual calibration. be able to.

Any fluid handling device (i.e., base unit) that is configured to operate diaphragm-based pumps and valves in a removable cassette utilizes its pneumatic (or hydraulic) cassette interface to operate a dedicated calibration cassette ( or a "cassette fixture"). The calibration cassette can have the same overall dimensions as a standard fluid pump cassette, thereby providing a sealed interface with the cassette interface or control surface of the base unit. One or more of the pump or valve regions may be enabled to communicate the corresponding region of the interface with which it mates, thereby connecting pneumatic or hydraulic flow paths of the base unit through the calibration cassette. A reference pneumatic or hydraulic pressure can be introduced within (eg, via a pneumatic or hydraulic manifold).

For example, in a pneumatically operated peritoneal dialysis cycler, the cycler's pneumatic circuitry may be directly accessed through the cycler's cassette interface. This can be accomplished, for example, with a modified cassette or cassette fixture that allows the control surface 148 to create a seal against the cassette fixture. Additionally, the cassette fixture can be configured to include at least one access port in fluid communication with the vacuum port 173B of the cassette interface. If there is no vacuum port (eg, in embodiments with slits or pores in the control surface), the access port can instead be placed in communication with the cassette interface or the vacuum vent mechanism of the control surface.

The cassette fixture (or calibration cassette) can be constructed to have a direct flow path from the external cassette port to the access port facing the device interface, and the external cassette port is available for connection to a pressure reference. be. As described above, all or some of the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 are placed in fluid communication with a common volume by suitably actuating pneumatic control valves in the pressure distribution manifold. can do. A pressure reference can be used to establish a known pressure within the volume. The pressure measurements from each of the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 can be compared to the known pressure of the pressure reference, and the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 are adjusted accordingly. can be calibrated.

In some embodiments of the pressure distribution manifold, it may not be possible for all of the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 to be connected to a common volume at one time. In that case, the flow paths to individual pressure sensors 2670, 2672, 2674, 2676, 2677, 2678 may need to be opened sequentially to ensure calibration of all sensors. Additionally, once calibrated, the pressure sensors 2670, 2672, 2674, 2676, in the pressure distribution manifold of the base unit or cycler using one or more of the pressure sensors 2670, 2672, 2674, 2676, 2677, 2678; It should be noted that 2677, 2678 can be calibrated. One or more previously calibrated pressure sensors can be placed in a common volume with an uncalibrated pressure sensor (eg, via suitable valving). The pressure of the common volume may be known via a calibrated pressure sensor. The measurements of the uncalibrated pressure sensor can be compared to the known pressure of a common volume and then calibrated accordingly.

FIG. 39 shows a schematic diagram of an embodiment of a cassette fixture 4570. As shown, the cassette fixture 4570 has the same external shape as the standard pump cassette 24 described above. Cassette fixture 4570 includes an access port 4572 associated with a predetermined valve or pump area of a standard cassette to align with a corresponding area of the cassette interface (control surface 148) of the base unit. The cassette fixture 4570 can have an otherwise flat smooth interface surface so that the control surface can be sealed against the base unit or cycler when mated thereto. Preferably, cassette fixture 4570 is formed from metal or other hard rigid material. Resistance to bending or deforming under pressure can help improve reliability and consistency across multiple calibrations of multiple cyclers. As shown, the cassette fixture 4570 includes an access port 4572 recessed in the face of the cassette fixture 4570. Access port 4572 communicates with a flow path 4573 that extends away from cassette fixture 4570 to a tube 4574. In example embodiments, a cassette port or fitting can be included on the side of the cassette to be connected via tubing to the reference pressure source 4576.

40 and 41 show other representations of a cassette fixture 4570 adapted from a modified cassette, such as cassette 24 shown in FIG. In such examples, the cassette fixture 4570 removes the sheet or membrane from the control side of the cassette that faces the control surface of the cycler or the cassette interface 148 (see, e.g., FIGS. 33A-C) when installed in the cycler. or by not including it. Referring to FIG. 3, for example, cassette 24 may not include membrane 15. Direct access to the cycler's pneumatic circuit is therefore possible through the cassette 24. Alternatively, the membrane or sheet can be interrupted (eg, removed, perforated, slit, etc.) in only a portion of the cassette to create cassette fixture 4570. For example, the membrane can be modified in this manner in the area where the access port 4572 of the cassette fixture 4570 is located.

Additionally, tubing 4574 can be attached to one or more of the external connection points of the standard cassette to create the necessary fluid communication paths for the cassette fixture 4570. External connection points can include any tube attachment points on a standard cassette, or can include more robust fittings for repeated use in calibration procedures. Referring to FIG. 3, external connection points can include cassette spike 160 and/or ports 150, 152 and 154. The cassette can then be modified so that it can be closed, plugged, or otherwise sealed for all other external connection points.

As discussed above, tube 4574 leads from fluid flow path 4573 that is fluidly connected to access port 4572 of cassette fixture 4570 to provide a connection to pressure reference 4576 . Access port 4572 can be an existing opening or valve port in the cassette body. Additionally, fluid passageway 4573 may be any existing passageway or combination of passageways in the cassette body that allows fluid communication from access port 4572 to tube 4574 or associated fittings on the cassette side. For example, the flow path 4573 can include one or more valve ports, valve wells, pump chambers, and/or cassette body channels, or any combination thereof.

As alluded to above, the cycler 14 may include a control system 16 with a data processor in electrical communication with the various valves, pressure sensors, motors, etc. of the system and preferably performs a desired operating sequence or It is configured to control such components according to a protocol. Control system 16 may include appropriate circuitry, programming, computer memory, electrical connections, and/or other components to perform specified tasks. The system provides a desired air or other fluid pressure (positive pressure above atmospheric pressure or some other standard, or atmospheric pressure or other It may include a pump, tank, manifold, valve, or other component that generates a negative pressure or vacuum (below some standard). Further details regarding control system 16 (or at least a portion thereof) are provided below.

In one exemplary embodiment, the pressure within pump control chamber 171B can be controlled by a binary valve, which opens to expose control chamber 171 to a suitable pressure/vacuum, for example, and Close to isolate pressure/vacuum source. The binary valve can be controlled using a sawtooth-shaped control signal that can be adjusted to control the pressure within the pump control chamber 171B. For example, during a pump delivery stroke (i.e., positive pressure is introduced into the pump control chamber 171B to move the membrane 15/control surface 148 and force liquid out of the pump chamber 181), the A binary valve can be driven by a sawtooth signal to open and close relatively quickly to establish a pressure of approximately 70 mmHg to 90 mmHg. If the pressure within control chamber 171B rises above about 90 mmHg, the sawtooth signal can be adjusted to close the binary valve for a longer period of time. If the pressure drops below about 70 mmHg within control chamber 171B, the sawtooth control signal can be applied again to the binary valve to increase the pressure within control chamber 171. Thus, during normal pump operation, the binary valve can be opened and closed multiple times and closed for one or more extended periods, such that the pressure at which liquid is forced out of the pump chamber 181 is at the desired level or range (eg, about 70 mmHg to 90 mmHg).

In some embodiments, and in accordance with aspects of the present disclosure, for example, when membrane 15 contacts spacer 50 of pump chamber 181 or pump control region 1482 contacts a wall of pump control chamber 171B, 15/It may be useful to detect the "end of stroke" of the pump control region 1482. For example, during a pumping operation, detection of "end of stroke" may cause the membrane 15/pump control region 1482 to initiate a new pump cycle (to fill or force fluid out of the pump chamber 181). It can be shown that the movement of should be reversed. In one exemplary embodiment where the pressure in the control chamber 171B for the pump is controlled by a binary valve driven by a sawtooth control signal, the pressure in the pump chamber 181 is controlled at a relatively high frequency, e.g. Varies at or near the frequency at which the valve is opened and closed. A pressure sensor in control chamber 171B can detect this variation, which generally occurs when membrane 15/pump control region 1482 is not in contact with the inner wall of pump chamber 181 or the wall of pump control chamber 171B. , has a relatively high amplitude. However, once the membrane 15/pump control region 1482 contacts the inner wall of the pump chamber 181, or the wall of the pump control chamber 171B (i.e., "end of stroke"), pressure fluctuations are generally detected by the pressure sensor in the pump control chamber 171B. Attenuates or otherwise changes in a detectable manner. This change in pressure fluctuation can be used to identify the end of stroke and the pump and other components of cassette 24 and/or cycler 14 can be controlled accordingly.

In one embodiment, air pressure applied to the control chamber 171B is provided by a pressure transducer 2672 (FIG. 38) connected to the control chamber 171B and a fast-acting binary valve X1A between the pressure reservoirs 2620, 2610 and the control chamber 171B. It is actively controlled by a processor that receives signals from X1B. The processor can control the pressure using various control algorithms including closed loop proportional or proportional-integral feedback control that changes the duty cycle of the valve to achieve the desired pressure within the control volume 171B. In one embodiment, the processor controls the pressure within the control chamber using an on-off controller, often referred to as a bang-bang controller. The on-off controller monitors the pressure in control volume 171B during the delivery stroke and opens binary valve X1B (connecting control volume 171B to positive pressure reservoir 2620) when the pressure is below a lower first limit. , closes the binary valve X1B when the pressure exceeds the second higher limit. During the filling stroke, the on-off controller opens binary valve X1A (connecting control volume 171B to negative pressure reservoir 2610) when the pressure is greater than a third limit, and opens binary valve X1A (connecting control volume 171B to negative pressure reservoir 2610) when the pressure is less than a fourth limit. Valve X1A is closed, where the fourth limit is less than the third limit, and the third and fourth limits are both less than the first limit. A plot of pressure over time, such as during the delivery stroke and subsequent FMS measurements, is shown in FIG. 114. Control chamber pressure 2300 oscillates between a lower first limit 2312 and a higher second limit 2310 as membrane 15 moves across control chamber 171B. When membrane 15 stops moving, the pressure stops oscillating between the limits. Membrane 15 typically stops moving when it contacts cassette arena stage 50 or when it contacts control chamber surface 171B. The membrane 15 can also stop moving if the outlet fluid line is occluded.

Automation computer (AC) 300 detects the end of the stroke by evaluating the pressure signal. There are many possible algorithms for detecting the end of a pressure oscillation indicating end of stroke (EOS). The section entitled "Detailed Description of the system and Method of Measuring Change Fluid Flow Rate" in U.S. Pat. No. 6,520,747, and the stroke To detect termination In the section describing filtering of EOS, algorithms and methods for detecting EOS are incorporated herein by reference.

One example of an algorithm for detecting EOS, AC 300, evaluates the time during which the pressure exceeds a first and second limit during a delivery stroke, or a third and fourth limit during a fill stroke. The on-off controller opens and closes valves X1A, X1B in response to pressure oscillating between two limits as the control chamber volume changes during a fill or delivery stroke. When the membrane 15 stops moving at the end of the stroke, the pressure change is significantly reduced so that the pressure no longer exceeds one or both limits. The AC 300 can detect EOS by measuring the time during which the pressure exceeds alternate limits. If the time since the pressure exceeded the last limit exceeds a predetermined threshold, the AC 300 may declare EOS. The algorithm may further include an initial stage in which the AC 300 does not measure the time between exceeding the limit.

In another example algorithm, AC 300 evaluates the derivative of the pressure signal with respect to time. If the derivative remains below the minimum threshold for the minimum time, the AC 300 may declare EOS. In a further example, the minimum threshold is the average of the absolute values of the average pressure derivatives during throat talk. The algorithm calculates the slope (derivative with respect to time) of a curve fit to a set of data points, where the data points are acquired from a moving window. The absolute value of the average pressure differential is then calculated by averaging the absolute value of each slope over the stroke. In another example of an EOS algorithm, the AC 300 may not include pressure data until after an initial delay. The AC 300 ignores initial pressure data to avoid inaccurate EOS detection due to irregular pressure traces that sometimes occur during the initial portion of the stroke. In another example, the AC 300 declares EOS only after the second derivative of pressure in a later portion of the stroke remains below a threshold for a minimum amount of time and a latency period has elapsed.

The criteria for declaring EOS can be optimized for different pumping conditions. Optimized EOS detection conditions include the second order pressure derivative threshold, the minimum amount of time that it remains below the second order derivative threshold, the duration of the initial delay, and the length of the waiting period. These EOS detection criteria may be optimized differently, for example, for fill strokes from the bags 20, 22, delivery strokes to the patient, fill strokes from the patient, and delivery strokes to the bags 20, 22. Can be done. Alternatively, each EOS detection criterion may be a function of pumping pressure within control chamber 171B.

Pump Delivery Volume Measurement In another aspect of the present invention, the cycler 14 is able to pump delivery volumes to the various lines of the system 10 without the use of flow meters, gravimeters, or other direct means of measuring fluid volume or weight. The volume of fluid can be determined. For example, in one embodiment, the volume of fluid moved by a pump, such as the pump in cassette 24, may be determined based on pressure measurements of the gas used to drive the pump. In one embodiment, the volume is determined by isolating two chambers from each other, measuring the pressure in each of the two isolated chambers, and (by fluidly connecting the two chambers) determining the pressure in the two chambers. This can be done by partially or substantially equalizing and measuring the pressure. Using the measured pressure, the known volume of one of the chambers, and the assumption that equalization occurs adiabatically, the volume of the other chamber (eg, pump chamber) can be calculated. In one embodiment, the pressures measured after the chambers are fluidly connected may not be substantially equal to each other, i.e., the pressures within the chambers may not yet fully equalize. be. However, as explained below, these substantially unequal pressures can be used to determine the volume of the pump control chamber.

For example, FIG. 43 shows a schematic diagram of the pump chamber 181 of the cassette 24 and associated control components and inflow/outflow paths. In this illustrative example, a liquid source, which may include heater bag 22, heater bag line 26, and a flow path through cassette 24, is configured to provide liquid input to pump chamber upper opening 191. It is shown. The liquid outlet is shown in this example to receive liquid from the lower opening 187 of the pump chamber 181 and may include, for example, the flow path of the cassette 24 and the patient line 34. The liquid source can include, for example, a valve including valve port 192 that can be opened and closed to allow/restrict flow to and from pump chamber 181. Similarly, the liquid outlet can include a valve, including, for example, valve port 190, which can be opened and closed to allow/restrict flow to and from pump chamber 181. It will be appreciated that the liquid source can include any suitable configuration, such as one or more solution containers, patient lines, one or more channels within cassette 24, or other liquid sources, The outlet may also include any suitable configuration, such as a drain line, a heater bag and heater bag line, one or more channels within the cassette 24, or other liquid outlets. Generally, pump chamber 181 (ie, to the left of membrane 14 in FIG. 43) is filled with an incompressible liquid, such as water or dialysate, during operation. However, in some situations, such as during initial operation, priming, or other situations as discussed below, air or other gases may be present within pump chamber 181. Additionally, although aspects of the invention relating to pump volume and/or pressure sensing are described with respect to the pump configuration of cassette 24, it is understood that aspects of the invention may be used with any suitable pump or fluid movement system. should be understood.

Figure 43 also schematically shows a control chamber 171B to the right of the membrane 15 and control surface 1482 (adjacent to each other), which is associated with the pump control area 1482 of the control surface 1482 for the pump chamber 181, as described above. may be formed as a void or other space in the mating block 170A. It is in the control chamber 171B that suitable air pressure is introduced to move the membrane 15/control region 1482 and pump the liquid in the pump chamber 181. The control chamber 171 can communicate with a line L0, which branches into another line L1 and a first valve X1 that communicates with a pressure source 84, for example a pneumatic source or a vacuum source. Pressure source 84 can include a piston pump, in which a piston moves within a chamber to control the pressure delivered to control chamber 171, or moves membrane 15/control region 1482 and Different types of pressure pumps and/or tanks can be included to deliver suitable gas pressures to perform the pumping action. Line L0 may also lead to a second valve X2 that communicates with another line L2 and a reference chamber 174 (eg, a space suitably configured to perform measurements as described below). Reference chamber 174 also communicates with line L3 having valve X3 leading to a vent or other reference pressure (eg, atmospheric pressure source or other reference pressure source). Each of valves X1, X2 and X3 can be controlled independently. Pressure sensors may be arranged to measure pressures associated with the control chamber and the reference chamber, for example, one sensor may be placed in the control chamber 171 and another sensor in the reference chamber. These pressure sensors can be arranged and operated to detect pressure in any suitable manner. The pressure sensor may communicate with a control system 16 for the cycler 14 or other suitable processor that determines the volume delivered by a pump or other mechanism.

as described above, to measure the pressure in the pump chamber 181, the liquid source and/or the liquid outlet, and/or to measure the volume of liquid delivered from the pump chamber 181 to the liquid source or the liquid outlet; Valves and other components of the pump mechanism shown in FIG. 43 can be controlled. Regarding volumetric measurements, one technique used to determine the volume of fluid delivered from the pump chamber 181 is to compare the relative pressure in the control chamber 171B to the pressure in the reference chamber at two different pump conditions. . By comparing the relative pressures, a change in the volume of the control chamber 171B can be determined, which corresponds to a change in the volume of the pump chamber 181 and reflects the volume delivered from/accepted to the pump chamber 181. . For example, during a pump chamber fill cycle, the pressure within control chamber 171B is reduced (e.g., by applying negative pressure through valve After drawing into contact with the portion (or into another suitable location of the membrane 15/region 1482), valve X1 can be closed to isolate the control chamber from the pressure source, and valve X2 can be closed. , thereby isolating the reference room from the control room 171B. Valve X3 can be opened to vent the reference chamber to atmospheric pressure and then closed to isolate the reference chamber. With valve X1 closed and the pressure in the control and reference chambers being measured, valve X2 is then opened to begin equalization of the pressures in the control and reference chambers. Using the initial pressures in the reference and control chambers, along with the known volume of the reference chamber and the pressure measured after equalization has begun (but not necessarily completed), calculate the control room volume. You can ask for it. The above process can be repeated when the seat 15/control area 1482 is pushed into contact with the spacer element 50 of the pump chamber 181 at the end of the pump delivery cycle. By comparing the control chamber volume at the end of the fill cycle to the volume at the end of the delivery cycle, the volume of liquid delivered from the pump can be determined.

Conceptually, the pressure equalization process (e.g., upon opening valve , seen as something that occurs. The conceptual idea is that when valve X2 is closed, a virtual piston is initially located in valve X2, and when valve X2 is opened, the virtual piston moves in line L0 or L2 to This is to equalize the pressure within the reference chamber. The pressure equalization process occurs because (a) the pressure equalization process occurs relatively quickly, (b) the air in the control and reference chambers have approximately the same concentrations of elements, and (c) the temperatures are similar. The assumption that adiabatic occurs may introduce only a small error in the volumetric measurements. Additionally, in one embodiment, the pressure obtained after equalization has begun can be measured before substantial equalization occurs and is the same as the initial pressure measurement used to determine the pump chamber volume. The time between final pressure measurements is further reduced. Furthermore, errors can be further reduced by using low thermal conductivity materials for the membrane 15/control surface 1482, cassette 24, control chamber 171, lines, reference chamber 174, etc. to reduce thermal conduction. can be reduced.

Assuming that an adiabatic system exists during the closed state of valve X2 until after valve X2 is opened and the pressure equalizes, the following equation applies.
PV ^γ = constant (1)
where P is pressure, V is volume, and γ is equal to a constant (eg, about 1.4 when the gas is diatomic, such as air). Therefore, the following equation can be written to relate the pressure and volume in the control chamber and reference chamber before and after valve X2 opens and pressure equalization occurs.

PrVr ^γ + PdVd ^γ = constant = PfVf ^γ (2)
where Pr is the pressure in the reference chamber and lines L2 and L3 before opening valve X2, Vr is the volume of the reference chamber and lines L2 and L3 before opening valve X2, and Pd is is the pressure in the control chamber and lines L0 and L1 before opening valve X2, Vd is the volume in the control chamber and lines L0 and L1 before opening valve X2, and Pf is the pressure after opening valve X2. where Vf is the volume of the entire system including the control room, reference chamber, and lines L0, L1, L2, and L3, i.e., Vf=Vd+Vr. Since Pr, Vr, Pd, Pf and γ are known and Vf=Vr+Vd, this formula can be used to solve for Vd (Here, when calculating the value of volume etc. '', it should be understood that such measured pressure values are not necessarily in any particular format, such as in psi units). Alternatively, "measured pressure" or "determined pressure" can include any value representative of pressure, such as an electrical potential, a resistance value, a multi-bit digital number, etc. For example, a pressure transducer used to measure the pressure within the pump control chamber may output an analog potential, resistance, or other indication representative of the pressure within the pump control chamber. The raw output from the transducer may be some form of pressure, such as the measured pressure and/or a digital number generated using the analog output from the transducer, psi or other value generated based on the transducer output. Can be used as output in a modified format. The same applies to other values, such as the determined volume, but not necessarily in a particular format, such as cubic centimeters. Alternatively, the determined volume can include any value representing volume, and can be used, for example, to generate an actual volume in cubic centimeters, for example.

In an embodiment of a fluid management system ("FMS") technique for determining the volume delivered by a pump, pressure equalization upon opening of valve X2 is assumed to occur in an adiabatic system. Therefore, Equation 3 below gives the relationship between the volumes of the reference chamber system before and after pressure equalization.

Vrf=Vri(Pf/Patm) ^-(1/γ) (3)
where Vrf is the final volume of the reference chamber system, including the volume of the reference chamber, the volume of lines L2 and L3, and the volume adjustment resulting from the movement of the "piston" that can move to the left or right of X2 after opening. (after equalization), Vri is the initial (before equalization) volume of the reference chamber and lines L2 and L3 with the "piston" in valve X2, and Pf is the initial (before equalization) volume of the reference chamber and lines L2 and L3 with the "piston" located in valve Patm is the initial pressure in the reference chamber (atmospheric pressure in this example) before valve X2 is opened. Similarly, Equation 4 gives the relationship between the volume of the control room system before and after pressure equalization.

Vdf=Vdi(Pf/Pdi) ^-(1/γ) (4)
where Vdf is the volume of the control room system, including the volume of the control room, the volume of lines L0 and L1, and the volume adjustment resulting from the movement of the "piston" that can move to the left or right of valve X2 after opening. is the final volume, Vdi is the initial volume of the control chamber and lines L0 and L1 with the "piston" in position in valve X2, Pf is the final pressure after valve X2 is opened, Pdi is the initial pressure in the control chamber before valve X2 is opened.

The volumes of the reference room system and the control room system change by the same absolute amount after valve X2 is opened and the pressures equalized, but with different signs, as shown in Equation 5 (e.g., when valve X2 is opened (This is because the change in volume is caused by the movement of the "piston" to the left or right when

ΔVr=(-l)ΔVd(5)
(Note that the change in volume of the reference and control chambers is due only to the movement of the virtual piston.The reference and control chambers actually change in volume during the equalization process under normal conditions. do not). Also, using the relationship from Equation 3, the volume change of the reference chamber system is given by the following equation:

ΔVr=Vrf-Vri=Vri(-1+(Pf/Patm) ^-(1/γ) ) (6)
Similarly, using Equation 4, the change in volume of the control room system is given by:

ΔVd=Vdf-Vdi=Vdi(-1+(Pf/Pdi) ^-(1/γ)) (7)
Since Vri is known and Pf and Patm are measured or known, ΔVr can be calculated, which is assumed to be equal to (−)ΔVd according to Equation 5. Therefore, Vdi (volume of the control room system before pressure equalization with the reference chamber) can be calculated using Equation 7. In this embodiment, Vdi represents the volume of the control room and lines L0 and L1, where L0 and L1 are fixed and known quantities. Subtracting L0 and L1 from Vdi yields the volume of the control room only. Equation 7 above can be used, for example, to determine the change in control chamber volume both before (Vdi1) and after (Vdi2) pump operation (e.g., at the end of the fill cycle and at the end of the drain cycle). and thus provides a measurement of the volume of fluid delivered by (or taken up by) the pump. For example, if Vdi1 is the control chamber volume at the end of the fill stroke and Vdi2 is the control chamber volume at the end of the subsequent delivery stroke, then the volume of fluid delivered by the pump is determined by subtracting Vdi1 from Vdi2. It can be estimated. Since this measurement is based on pressure, the determination of the volume can be performed for almost any position of the membrane 15/pump control area 1482 in the pump chamber 181, whether for a complete pump stroke or a partial pump stroke. It can be done by However, measurements made at the end of fill stroke talk and end of delivery stroke can be accomplished with little or no effect on pump operation and/or flow rate.

One aspect of the present invention includes techniques for identifying pressure measurements used for volume determination and/or other purposes for a control room. For example, a pressure sensor can be used to detect the pressure in the control chamber and the pressure in the reference chamber. It may change depending on ventilation, etc. to the reference pressure of. Also, in one embodiment, it is assumed that an adiabatic system exists between the control room and the reference room from before pressure equalization to after pressure equalization, so that appropriate pressure values measured close in time can be used. can help reduce errors (e.g., because less time elapses in the pressure measurement can reduce the amount of heat exchanged in the system). Therefore, the measured pressure value may need to be carefully selected to help ensure that the appropriate pressure is used to determine the volume delivered by the pump or the like.

As mentioned above, L3 in FIG. 43 can have a valve X3 leading to a vent. In some embodiments, the vent can communicate with the atmosphere, or in other embodiments with another reference pressure. In some embodiments, this vent can be connected to the control chamber 171B via a valve so that the control chamber can be vented (see, eg, FIG. 38). In conventional devices, vents were used to bring the control chamber 171B from negative pressure after the fill stroke to ambient pressure before positive pressurization of the control chamber 171B. This allows the control chamber 171B to have a higher starting pressure before being connected to the pressure source 84, thus minimizing pressure depletion in the positive pressure source or reservoir 84. As a result, the pump feeding the positive pressure reservoir needs to operate less frequently.

On the other hand, it may be advantageous in some scenarios to then vent the already positive pressure control chamber 171B to a lower pressure before positively repressurizing the chamber later for FMS measurements. It was judged. This new step requires additional effort (e.g., pump run time) to maintain the pressure source 84 at its pressure set point (e.g., if the line leading to or from the associated pump chamber is blocked). This can be done to help alleviate any possible undesirable effects from backpressure (due to partial occlusion or due to partial occlusion). Additionally, this can help improve the overall accuracy of volumetric (volume) measurements and fluid calculations. One possible reason for this is that the pump chamber outlet valve 190 (in this case, a pneumatically actuated membrane valve) may not close efficiently when the control chamber 171B remains positively pressurized. That's what it means.

In some embodiments, the control system 16 of the cycler 14 may vent the control chamber 171B prior to making measurements to determine the delivered or filled fluid volume. Additionally, in some embodiments, the control system 16 of the cycler 14 may vent the first control chamber 171B prior to performing pumping operations with the second control chamber contained in the installed cassette 24.

In the example embodiment shown in FIG. 43, this venting or backpressure relief can be accomplished by opening valves X2 and X3 and closing valve X1. Therefore, the control chamber 171B can be arranged so as to communicate with the ventilation hole via the reference chamber 174. Of course, in other embodiments, the control chamber 171B can be placed in more direct communication with the vents. For example, additional valves can be included associated with fluid passages that are in direct communication with the vents. Any other suitable configuration may also be used.

In some embodiments, the control chamber 171B can be vented by placing the control chamber 171B in fluid communication with the vents for a suitable or predetermined period of time. In other embodiments, the control system 16 of the cycler 14 is associated with one or both of the control chamber 171B or the reference chamber 174 (or a control system, such as a pressure dispersion module, etc.) to control venting of the control chamber 171B. Data from a pressure sensor (located in fluid communication with the chamber) can be used. In such embodiments, data from the pressure sensor may be used to determine whether the control chamber 171B is sufficiently vented. Once the control room 171B is determined to be sufficiently vented, the control system 16 of the cycler 14 can close the appropriate valves to isolate the control room 171B from the vent. The pressure in the control chamber 171B does not necessarily need to completely equalize the pressure in the vent for the control system 16 to determine that the control chamber 171B is sufficiently vented.

In some embodiments, control chamber 171B may instead be exposed to a source of negative pressure for a suitable or predetermined period of time to vent backpressure within control chamber 171B. In such embodiments, control chamber 171B may be placed in communication with pressure source 84. In the example embodiment shown in FIG. 43, this can be accomplished by opening valve X1 and closing at least valve X3. In the case of a positively pressurized control chamber 171B, the pressure source to which the control chamber 171B is connected may be a negative pressure source. In some embodiments, the control system 16 of the cycler 14 may only open the valve to the negative pressure source for short periods of time. The short period is sufficient time to bring the pressure within the control chamber 171B within a predetermined range of predetermined values (in the example, this may be approximately atmospheric pressure) before it can equalize with the pressure source. It can be. In other embodiments, valve X1 can be adjusted to provide the same effect. If it is a variable valve, its orifice opening can be adjusted by the controller, and if it is a binary valve, the controller can adjust the rate and magnitude of pressure delivery across the valve, for example using pulse width modulation. can do.

For purposes of illustration, FIG. 44 shows an example diagram for the control and reference chambers from a time before opening of valve X2 to some time after valve X2 has been opened to equalize the pressure in the chamber. shows a plot of typical pressure values. In this exemplary embodiment, the pressure within the control chamber is higher than the pressure within the reference chamber prior to equalization; however, the control chamber pressure may be higher than the pressure within the reference chamber prior to equalization; It should be understood that it may be lower than the previous reference chamber pressure. Also, although the plot in FIG. 44 shows a horizontal line marking the equalization pressure, it should be understood that this line is shown for clarity only. The equalization pressure is generally not known before opening of valve X2. In this embodiment, the pressure sensor detects pressure at a rate of approximately 2000 Hz for both the control and reference chambers, although other suitable sampling rates can be used. Before the opening of valve X2, the pressure in the control and reference chambers is approximately constant and no air or other fluid is introduced into the chambers. Therefore, valves X1 and X3 are generally closed before opening of valve X2. Additionally, valves leading into the pump chamber, such as valve ports 190 and 192, may be closed to prevent the effects of pressure fluctuations in the pump chamber, liquid source, or liquid outlet.

First, the measured pressure data is processed to determine the initial pressures, ie, Pd and Pr, for the control and reference chambers. In one exemplary embodiment, the initial pressure is determined based on analysis of a 10 point sliding window used on the measured pressure data. This analysis involves generating a line of best fit for the data in each window (or set) using, for example, a least squares method and determining the slope of the line of best fit. For example, each time a new pressure is measured for a control or reference room, a least squares fit line can be determined for a data set that includes the most recent measurement and nine previous pressure measurements. This process can be repeated for several sets of pressure data, with the slope of the least-squares fit line first becoming negative (or non-zero) and progressing further to the negative for subsequent data sets. A judgment can be made as to when to continue (or deviate from zero slope). The point at which the least squares fit line begins to have a suitable increasing non-zero slope can be used to determine the initial pressure in the chamber, ie, the pressure at the time before valve X2 is opened.

In one embodiment, the initial pressure values for the reference and control rooms may be determined to be at the end of five consecutive data sets, where the slope of the best fit line for those data sets is 1 data set to a fifth data set, and the slope of the line of best fit for the first data set is initially non-zero (i.e., the slope of the line of best fit for the data set preceding the first data set is zero or not sufficiently non-zero). For example, the pressure sensor may sample every 1/2 millisecond (or other sampling rate) starting at a time before valve X2 opens. Each time a pressure measurement is taken, cycler 14 can take the most recent measurement along with the previous nine measurements and generate a best fit line for the ten data points in the set. Upon taking the next pressure measurement (e.g., 1/2 millisecond later), the cycler 14 takes the measurement along with the nine previous measurements and again uses the best fit line for the 10 points in the set. can be generated. This process may be repeated, and the cycler 14 determines, e.g. It can be determined that the slope of the best fit line for five subsequent sets of data points increases with each subsequent data set. To identify a predetermined pressure measurement to use, one technique is to use a fifth data set (i.e., the best fit line is selecting a third measurement value in the fifth data set) that is found to increase with a consistent slope and the first measurement being the pressure measurement taken earliest in time. This choice was made using an empirical method, for example, by plotting the pressure measurements and then selecting the point that best represents the point at which the pressure begins the equalization process. Of course, other techniques can be used to select an appropriate initial pressure.

In one exemplary embodiment, it is possible to verify that the time points at which the selected Pd and Pr measurements were taken were within a desired time threshold, e.g., within 1-2 milliseconds of each other. can. For example, if control and reference chamber pressures are analyzed using the techniques described above and a pressure measurement (and thus a point in time) is determined just before pressure equalization begins, then the point in time at which the pressure was measured is , should be relatively close to each other. Otherwise, there may have been an error or other fault condition that invalidated one or both of the pressure measurements. By verifying that the points at which Pd and Pr occur are appropriately close to each other, cycler 14 can confirm that the initial pressure has been properly determined.

To identify when the pressures in the control chamber 171B and the reference chamber 174 have equalized so that the measured pressure on the chamber can be used to reliably determine the pump chamber volume, the cycler 14 Analyze a data set containing a series of data points from pressure measurements for both reference chambers, determine a best fit line (e.g., using least squares) for each of the data sets, and determine the data for control room 171B. It is possible to identify when the slopes of the best-fit lines for the dataset and the reference chamber 174 are initially suitably similar to each other, e.g., when the slopes both have values close to zero or within a threshold of each other. can. When the slopes of the best fit lines are similar or close to zero, the pressure can be determined to have equalized. The first pressure measurement for either data set can be used as the final equalized pressure, or Pf. In one exemplary embodiment, pressure equalization generally occurs within about 200 to 400 milliseconds after valve X2 is opened, with the majority of equalization occurring within about 50 milliseconds. I found out that I did it. Therefore, the pressure in control chamber 171B and reference chamber 174 increases approximately 400 to 800 or more times during the entire equalization process, from the time before valve X2 is opened until the time equalization is achieved. Can be sampled.

In some cases, it may be desirable to use alternative FMS techniques to improve the accuracy of control room 171B volume measurements. Substantial differences in temperature between the liquid being pumped and the control chamber 171B gas and the reference chamber gas can introduce significant errors into calculations based on the assumption that pressure equalization occurs adiabatically. be. Waiting to take pressure measurements until there is sufficient pressure equalization between control chamber 171B and reference chamber 174 may generate an excessive amount of heat transfer. In one aspect of the invention, pump chamber 181 and reference chamber pressure values that are not substantially equivalent to each other, i.e., measured before complete equalization has occurred, may be used to determine the pump chamber volume. .

In one embodiment, heat transfer is minimized by measuring chamber pressure throughout the equalization period from opening of valve X2 through full pressure equalization and selecting sampling points during the equalization period for adiabatic calculations. It is possible to reduce adiabatic calculation errors. In one embodiment of the APD system, the measured chamber pressure, obtained before any pressure equalization between the control chamber 171B and the reference chamber 174, can be used to determine the pump chamber 181 volume. In one embodiment, these pressure values can be measured approximately 50 milliseconds after the chambers are first fluidically connected and equalization is initiated. As mentioned above, in one embodiment, complete equalization may occur approximately 200 milliseconds to 400 milliseconds after valve X2 is opened. Therefore, the measured pressure can be obtained at a time after valve X2 is opened (or equalization has started), which is no more than about 10% to 50% of the total equalization period. . In other words, the measured pressure can be taken at the point where 50% to 70% of the pressure equalization has occurred (i.e., the reference chamber 174 and pump chamber 181 pressures are different from the initial chamber pressure and the final equalization pressure. A computer-enabled controller is used to take, store, and analyze a substantial number of pressure measurements in the control room and reference room during the equalization period. (e.g. 40 to 100 individual pressure measurements).There is a theoretically optimized sampling point for performing adiabatic calculations among the time points sampled during the first 50 ms of the equalization period. (See, for example, FIG. 44, where the optimized sampling point occurs approximately 50 milliseconds after valve X2 opens.) The optimized sampling point occurs between the gas volumes of the two chambers. Occurs early enough after opening of valve X2 to minimize heat transfer, but early enough to introduce significant errors in pressure measurement due to pressure sensor characteristics and valve actuation delays. However, as shown in Figure 44, the pressures on the pump chamber and reference chamber may not be substantially equal to each other at this point, and therefore equalization may not be complete. In some cases, it may be technically difficult to obtain a reliable pressure measurement immediately after the opening of valve X2, due to, for example, the inherent inaccuracy of the pressure sensor, This is due to the time required for opening and the sudden initial change in pressure in either the control chamber 171B or the reference chamber 174 immediately after the opening of the valve X2, etc.).

During pressure equalization, when the final pressures for control chamber 171B and reference chamber 174 are not the same, Equation 2 becomes:
PriVri ^γ + PdiVdi ^γ = constant = PrfVrf ^γ + PdfVdf ^γ (8)
In the formula, Pri=pressure in the reference chamber before opening valve X2, Pdi=pressure in the control chamber before opening valve X2, Prf=final reference chamber pressure, and Pdf=final control chamber pressure.

An optimization algorithm can be used to select a point during the pressure equalization period at which the difference between the absolute values of ΔVd and ΔVr is minimized (or below a desired threshold) over the equalization period. (In an adiabatic process, this difference should ideally be zero, as shown by Equation 5. In Figure 104, the point at which the difference between the absolute values of ΔVd and ΔVr is minimized is 50 mm. (occurs at the second line, where it is marked ``When the final pressure is determined''). Initially, pressure data can be collected from the control room and the reference room at multiple points j=1 to n between the opening of valve X2 and the final pressure equalization. Since Vri, i.e. the fixed volume of the reference chamber system before pressure equalization, is known, the subsequent value for Vrj (reference chamber system volume at sampling point j after valve X2 is opened) is determined by the equalization curve can be calculated using Equation 3 at each sampling point Prj along . For each such value of Vrj, the value for ΔVd can be calculated using Equation 5 and Equation 7, such that each value of Vrj is equal to Vdij, the estimated value for Vdi, Bringing the volume of the control room system. Using each value of Vrj and its corresponding value of Vdij and using Equation 3 and Equation 4, calculate the difference in the absolute values of ΔVd and ΔVr at each pressure measurement point along the equalization curve. I can do it. The sum of the squares of these differences provides a measure of the error in the calculated value of Vdi during pressure equalization for each value of Vrj and its corresponding Vdij. Let Prf be the reference chamber pressure that yields the minimum sum of the squared differences of |ΔVd| and |ΔVr|, and let its associated reference chamber volume be Vrf, then optimize Vdi using the data points Prf and Pdf corresponding to Vrf. The estimated value, i.e., the control room system initial volume, can be calculated.

One way to find a location on the equalization curve that complements the optimized values for Pdf and Prf is as follows.
1) Collect a series of pressure data sets from the control room and the reference room starting just before opening valve X2 and ending with Pr and Pd approaching equal values. If Pri is the first reference chamber pressure captured, subsequent sampling points in FIG. 104 are Prj=Pr1, Pr2, . ．． ．． It is called Prn.

2) For each Prj after Pri, calculate the corresponding ΔVrj using Equation 6 (where j represents the jth pressure data point after Pri).
ΔVrj=Vrj-Vri=Vri(-1+(Prj/Pri) ^-(1/γ) )
3) For each such ΔVrj, calculate the corresponding Vdij using Equation 7.
for example,
ΔVr1=Vri*(-1+(Pr1/Pri) ^-(1/γ) )
ΔVd1=-ΔVr1
therefore,
Vdi1=ΔVd1/(-1+(Pd1/Pdi) ^-(1/γ) )
Vdin=ΔVdn/(-1+(Pdn/Pdi) ^-(1/γ) )
During pressure equalization, a set of n control room system initial volumes (Vdi1 to Vdin) are calculated based on a set of reference room pressure data points Pr1 to Prn, over the entire pressure equalization period. A time point (f) can be selected that results in an optimized measurement of the control room system initial volume (Vdi).

4) Using Equation 7, calculate all ΔVdj,k using control chamber pressure measurements Pd for time points k=1-n for each of Vdi1-Vdin.
For Vdi corresponding to Pr1,
ΔVd1,1=Vdi1*(-1+(Pd1/Pdi) ^-(1/γ) )
ΔVd1,2=Vdi1*(-1+(Pd2/Pdi) ^-(1/γ) )
ΔVd1,n=Vdi1*(-1+(Pdn/Pdi) ^-(1/γ) )
For Vdi corresponding to Prn,
ΔVdn, l=Vdin*(-1+(Pd1/Pdi) ^-(1/γ) )
ΔVdn, 2=Vdin*(-1+(Pd2/Pdi) ^-(1/γ) )
ΔVdn, n=Vdin*(-1+(Pdn/Pdi) ^-(1/γ) )
5) Calculate the sum of squared errors between the absolute values of ΔVr and ΔVdj,k.

[S1 is the value of |ΔVd|−|ΔVr| over all data points during the equalization period when determining Vdi from Vr1 and ΔVr using the first data point Pr1, that is, the initial volume of the control chamber system. Represents the sum of squared errors. ]

[S2 is the calculation of |ΔVr|−|ΔVd| over all data points during the equalization period when determining Vdi from Vr2 and ΔVr using the second data point Pr2, that is, the initial volume of the control room system. Represents the sum of squared errors. ]

6) Then the Pr data point between Pr1 and Prn that produces the least squared error sum S (or a value less than the desired threshold) from some step 5 becomes the selected Prf, from which Pdf, and Vdi An optimized estimate, ie, an initial control room volume, can be determined. In this example, Pdf occurs at or near the same time as Pr.

7) The above procedure can be applied whenever an estimate of the control chamber volume is desired, but preferably at the end of each fill stroke and at the end of each feed stroke. The difference between the optimized Vdi at the end of the fill stroke and the optimized Vdi at the end of the corresponding delivery stroke can be used to estimate the volume of liquid delivered by the pump.

Air Detection Another aspect of the present invention includes determining the presence of air within pump chamber 181 and, if present, the volume of air present. Such determinations may help ensure that the priming procedure was performed properly to remove air from the cassette 24, for example, and/or may help ensure that no air is delivered to the patient. may be important for In some embodiments, for example, when delivering fluid to a patient through the lower opening 187 at the bottom of the pump chamber 181, air or other gases trapped in the pump chamber tend to remain within the pump chamber 181. The gas is prevented from being pumped to the patient unless the volume of the gas is greater than the volume of the effective dead space of the pump chamber 181. As discussed below, in accordance with aspects of the invention, the volume of air or other gas contained in pump chamber 181 may be determined before the volume of gas becomes greater than the volume of effective dead space in pump chamber 181. Gas can be purged from the pump chamber 181.

Determination of the amount of air in the pump chamber 181 can be made at the end of the filling stroke and thus without interrupting the pumping process. For example, at the end of the filling stroke when the membrane 15 and pump control area 1482 are pulled away from the cassette 24 so that the membrane 15/area 1482 comes into contact with the wall of the control chamber 171, valve X2 can be closed. , for example, by opening valve X3, the reference chamber can be vented to atmospheric pressure. Valves X1 and X3 can then be closed, fixing the virtual "piston" in valve X2. Valve X2 can then be opened and the pressure in the control and reference chambers equalized as described above when taking pressure measurements to determine the volume of the control chamber.

If there are no air bubbles in the pump chamber 181, the change in volume of the reference chamber determined using the known initial volume of the reference chamber system and the initial pressure of the reference chamber, i.e., due to movement of the virtual "piston" is equal to the change in control room volume determined using the known initial volume of the control room system and the initial pressure in the control room. (The initial volume of the control chamber may be known with the membrane 15/control region 1482 in contact with the wall of the control chamber or with the spacer element 50 of the pump chamber 181.) However, the pump When air is present within chamber 181, the change in control chamber volume is actually distributed between the control chamber volume and the air bubble within pump chamber 181. As a result, using a known initial volume of the control room system, the calculated volume change for the control room will not be equal to the calculated volume change for the reference room, and therefore the presence of air in the pump chamber will not be detected. be done.

If there is air in the pump chamber 181, the initial volume Vdi of the control room system is actually the sum of the volumes of the control chamber and lines L0 and L1 (referred to as Vdfix) + pump chamber 181, as shown in Equation 9. is equal to the initial volume of the bubble within (referred to as Vbi).

Vdi=Vbi+Vdfix(9)
With the membrane 15/control area 1482 pressed against the control chamber wall at the end of the filling stroke, for example, the presence of grooves or other features in the control chamber wall and the volume of lines L0 and L1 (together Vdfix), the volume of any air space in the control room can be known with great accuracy. (Likewise, with the membrane 15/control area 1482 pressed against the spacer element 50 of the pump chamber 181, the volume of the control chamber and lines L0 and L1 can be precisely known). After the fill stroke, the volume of the control room system is tested using a positive pressure control room precharge. Any difference between this tested volume and the tested volume at the end of the fill stroke can indicate the volume of air within the pump chamber. By substituting Equation 9 into Equation 7, the change in volume of the control room ΔVd is given by the following equation.

ΔVd=(Vbi+Vdfix)(-1+(Pdf/Pdi) ^-(1/γ) )(10)
ΔVr can be calculated from Equation 6, and from Equation 5 it can be seen that ΔVr=(−1)ΔVd, so Equation 10 can be rewritten as follows.

(-l)ΔVr=(Vbi+Vdfix)(-1+(Pdf/Pdi) ^-(1/γ) )(11)
And again, it can be rewritten as follows.

Vbi=(-1)ΔVr/(-l+(Pdf/Pdi) ^-(1/γ) )-Vdfix(12)
Therefore, cycler 14 can use Equation 12 to determine whether there is air in pump chamber 181 and the approximate volume of the bubbles. This bubble volume calculation can be performed, for example, if the absolute values of ΔVr (as determined from Equation 6) and ΔVd (as determined from Equation 7 using Vdi=Vdfix) are found to be unequal to each other. , can be done. That is, if there is no air in the pump chamber 181, Vdi should be equal to Vdfix, and therefore the absolute value of ΔVd given by Equation 7 using Vdfix instead of Vdi will be equal to ΔVr.

If air is detected after the filling stroke is completed and according to the method described above, it is difficult to determine whether the air is located on the pump chamber side or the control side of the membrane 15. there is a possibility. Air bubbles may be present in the liquid being pumped, or conditions during pumping (e.g., blockages, etc.) that result in an incomplete pump stroke and incomplete pump chamber filling may cause the pump diaphragm 15 to There may be residual air on the control (pneumatic) side. At this point, adiabatic FMS measurements can be performed using a negative pressure pump chamber precharge. If this FMS volume matches the FMS volume with a positive pressure precharge, the membrane can move freely in both directions, which means that the pump chamber is only partially filled (in some cases, e.g. due to occlusion). suggests that it is. When the membrane 15/region 1482 contacts the inner wall of the control chamber, if the value of the pump chamber precharge FMS volume at negative pressure is equal to the nominal control chamber air volume, air bubbles will form in the fluid on the pump chamber side of the flexible membrane. It is possible to conclude that there is.

Polytropic FMS for pump delivery volume measurement
In another aspect of the present disclosure, the cycler 14 of FIG. 1A can be delivered in various lines of the system 10 without the use of flow meters, gravimeters, or other direct measurements of fluid volume or weight. The volume of fluid can be determined. For example, in one embodiment, the volume of fluid moved by a diaphragm pump, such as a pneumatically driven diaphragm pump including cassette 24, can be determined based on pressure measurements of the gas used to drive the pump.

In one embodiment, volume determination is accomplished by a process referred to herein as a two-chamber fluid measurement system (two-chamber FMS) process. The volume of fluid pumped by a diaphragm pump can be calculated from the change in volume of the pneumatic chamber on one side of the diaphragm. The volume of the pneumatic chamber can be measured at the end of each fill and delivery stroke, with the difference in volume between subsequent measurements being the volume of fluid displaced by the pump.

The volume of the pneumatic chamber or first chamber is determined by closing the liquid valves inside and outside the diaphragm pump, isolating the first chamber from a second chamber (reference chamber) of known volume, and placing the first chamber at a first pressure. precharging a second chamber to a second pressure while precharging the second chamber to a second pressure, and then fluidly connecting the two chambers; and at least an initial pressure and a final pressure in each chamber as the pressures equalize. measured by a two-chamber FMS process. The volume of the first chamber can be calculated from at least the initial and final pressures and the known volume of the second chamber.

If the first chamber is precharged to a pressure that exceeds the pressure in the second chamber, the two-chamber FMS process is referred to as positive pressure FMS or +FMS. If the first chamber is precharged to a pressure below the pressure in the second chamber, the two-chamber FMS process is referred to as negative pressure FMS or -FMS. Referring now to FIG. 45, the first chamber is the control chamber 6171 and the second chamber is the reference chamber 6212.

The type of algorithm for calculating the first chamber volume may depend on the heat transfer characteristics of the first chamber and the second chamber and the fluid line connecting the two chambers. The amount of heat transfer between the structure and the gas during equalization affects the pressure in both the first and second chambers during and after equalization. During equalization, the gas in the higher pressure chamber expands toward the other chamber. This expanded gas is cooled to a lower temperature and therefore to a lower pressure. The temperature drop and loss of pressure of the expanding gas may be slowed or reduced by heat transfer from hotter structures. At the same time, the gas in the chamber, which is initially at low pressure, is compressed during equalization. The temperature of this compressed gas increases with pressure. The heating and pressure increase of the compressed gas may be slowed or reduced by heat transfer from cooler structures.

The relative importance of heat transfer between the structure (chamber walls, solid materials within the chamber) and the gas is a function of the average hydraulic diameter of the chamber, the thermal diffusivity of the gas, and the duration of the equalization process. . In one example, the two volumes have sufficient surface area and heat so that the gas temperature is constant within each chamber during pressure equalization so that the expansion and compression processes can be modeled as being isothermal. Filled with heat absorbing material, such as foam or other matrix, which provides mass. In another example, the two chambers are sized and shaped to provide negligible heat transfer, so the expansion and compression processes can be modeled as being adiabatic. In another example, the shape and size of control chamber 6171 changes from measurement to measurement. As measured after the fill stroke, if the control chamber 6171 is small and all of the gas is relatively close to the chamber wall 6170 or membrane 6148, the heat transfer between the gas and the structure is significant. As measured after the delivery stroke, control chamber 6171 is large and open, so much of the gas is relatively isolated from chamber wall 6170 or diaphragm 6148, and there is negligible heat transfer to the gas. As measured after a partial stroke, the heat transfer between the structure and the gas is significant, but not sufficient to ensure a constant temperature. In all these measurements, the expansion and compression processes can be modeled as polytropic, and the relative importance of heat transfer can change from measurement to measurement. The polytropic model accurately models the equalization process for all geometries and can incorporate the effects of different levels of heat transfer within the first and second chambers. A more detailed model of the equalization process more accurately determines the volume of the first chamber from knowledge of the pressure and volume of the second chamber.

This section describes an algorithm to calculate the volume of the first chamber 6171 for a polytropic two-chamber FMS process. The first subsection describes a two-volume FMS or two-chamber FMS process for an exemplary arrangement of volumes, pressure sources, valves, and pressure sensors. The following subsections conceptually describe the polytropic FMS algorithm for data from the +FMS process and then present the exact formula for calculating the first volume from the pressure data. The next subsection presents the concepts and formulas of the polytropic FMS algorithm for data from the -FMS process. The final subsection presents the process of calculating the volume of the first chamber 6171 using either set of equations.

The model described can be applied to any system or device that uses pneumatically operated diaphragm pumps. The components of the system include a diaphragm pump having at least one chamber inlet or outlet with a valved connection to either a fluid source or a fluid destination and a positive or negative pressure in the pump chamber for fluid delivery or filling. a pneumatic control chamber separated from the pump chamber by a diaphragm for providing pressure, the pneumatic control chamber having a reference chamber of known volume and a valved connection to a source of positive or negative pressure; controls the system's valves and monitors air pressure in the control and reference chambers. FIG. 45 schematically depicts an example system, although the specific configuration of inlets, outlets, and fluid and pneumatic conduits and valves may vary somewhat from this illustration. The following description uses a peritoneal dialysis cycler and pump cassette as an example, but the invention is in no way limited to this particular application.

Hardware for the Two-Chamber FMS Process Referring now to FIG. 45, FIG. 45 schematically presents the elements of the cycler and cassette 624 involved in the two-chamber FMS process. Cassette 624 includes two liquid valves 6190, 6192 that are fluidly connected to a liquid source 6193 and a liquid outlet 6191. Cassette 624 includes a diaphragm pump with variable liquid volume pump chamber 6181 separated from control chamber 6171 by flexible membrane 6148. The volume of control chamber 6171 is defined by membrane 6148 and chamber wall 6170. Control room 6171 is the first chamber of unknown volume mentioned above.

Control line 6205 also communicates with connection valve 6214, which communicates with reference line 6207 and reference chamber 6212 (eg, a space suitably configured to perform measurements as described below). Reference chamber 6212 is a second chamber having a known volume as described above. The reference chamber 6212 also communicates with an outlet line 6208 having a second valve 6216 leading to a vent 6226 to atmospheric pressure. In another example, vent 6226 can be a reservoir controlled to a desired pressure by one or more pneumatic pumps, pressure sensors, and controllers. Valves 6220, 6214 and 6216 can be independently controlled by controller 61100.

Pressure source 6210 is selectively connected to control chamber 6171 via lines 6209 and 6205. Pressure source 6210 can include one or more separate reservoirs held at different specified pressures by one or more pneumatic pumps. Each pneumatic pump can be controlled by controller 61100 to maintain a specified pressure in each reservoir as measured by a pressure sensor. A first valve 6220 can control the fluid connection between the pressure source 6210 and the control chamber 6171. Controller 61100 can selectively connect one of the reservoirs in pressure source 6210 to line 6209 to control the pressure within the control chamber as measured by pressure sensor 6222. In some examples, controller 1100 may be part of a larger control system in an APD cycler.

Control chamber 6171 is connected to control pressure sensor 6222 via line 6204. A reference pressure sensor 6224 can be connected to the reference chamber 6212 via line 6203. Pressure sensors 6222, 6224 may be electromechanical pressure sensors that measure absolute pressure, such as the MPXH6250A manufactured by Freescale Semiconductors of Japan. Control pressure sensor 6222 and reference pressure sensor 6224 are connected to controller 61100, which records the control pressure and reference pressure for subsequent volume calculations. Alternatively, pressure sensors 6222, 6224 may be relative pressure sensors that measure the pressure in the control and reference chambers relative to ambient pressure, and controller 61100 may include absolute pressure sensors that measure ambient pressure. . Controller 61100 may combine the relative pressure signals from sensors 6222, 6224 and the absolute ambient pressure sensor to calculate the absolute pressure in control chamber 6171 and reference chamber 6212, respectively.

The FMS hardware shown in FIG. Valves and other components can be controlled. Controller 61100 may be a single microprocessor or multiple processors. In one example, the pressure signal is received by the AD board and buffered before being passed to the 61100 controller. In another example, a field programmable gate array (FPGA) can handle all I/O between the controller 61100 and the valves and sensors. In another example, the FPGA can filter, store, and/or process pressure data to calculate control room volume.

Two-Chamber FMS Process in an APD Cycler Reference is now made to the pressure versus time plot in FIG. 46 and the elements of FIG. 45. An exemplary pumping and measurement process is depicted in a plot of control chamber pressure 6300 and reference chamber pressure 6302 versus time. As described above, after closing inlet valve 6192 and opening outlet valve 6190, chamber pressure is controlled relative to positive pressure valve 6305, which forces fluid out of pump chamber 6181 during delivery stroke 6330. At the end of the delivery stroke 6330, the outlet fluid valve is closed and the +FMS process can occur to measure the volume of the control chamber 6171. The FMS process, as described elsewhere, may consist of bringing the control chamber pressure 6330 to the precharge pressure 6307 and allowing a pressure stabilization period 6338 followed by an equalization process 6340. In other examples, control chamber pressure 6330 may be returned to approximately atmospheric pressure before increasing to precharge pressure 6307. At the end of the equalization process 6340, the reference chamber pressure 6302 and possibly the control chamber pressure 6300 may be returned to approximately atmospheric pressure values.

The fill stroke 6320 occurs after opening the inlet valve 6192, bringing the control chamber pressure 6300 to a negative pressure 6310, while the reference chamber remains at approximately atmospheric pressure, or a constant measured pressure. The negative pressure draws fluid into the pump chamber 6181. At the end of the fill stroke 6320, the inlet valve 6192 is closed and the +FMS process can occur to determine the volume of the control chamber 6171. In some embodiments, a -FMS process can occur after a +FMS process. - The FMS process may include precharging the control chamber to negative pressure 6317 to enable pressure stabilization 6342 and finally equalization process 6345. The control chamber volume determined from the -FMS process can be compared to the control chamber volume determined from the +FMS process to determine whether there is a volume of air or gas within the pump chamber 6181. (For example, if the pump chamber includes an air trap with ribs or standoffs on the pump chamber rigid wall, air can accumulate between the standoffs, and the diaphragm in full range of motion is In one example, the -FMS process occurs after delivery stroke 6330.

The +FMS and -FMS processes will be described in more detail with reference to the flowchart of FIG. 47, the elements of FIG. 46, and the pressure versus time plots of FIGS. 48A and 48B. The two-chamber FMS process begins at step 6410, where the position of membrane 6148 is fixed. By closing both hydraulic valves 6190, 6192, the position of membrane 6148 can be fixed. In some examples, when air bubbles are present in the liquid, the position of the membrane 6148 changes as the control chamber pressure changes. However, the volume of uncompressible liquid between hydraulic valves 6190, 6192 is fixed. A two-chamber FMS process generally measures the volume of air or gas on both sides of the membrane 6148, so that an air bubble in the pump chamber 6181 on the liquid side of the membrane 6148 is contained within the measured volume of the control chamber 6171. .

At step 6412, control chamber 6171 is fluidly isolated from reference chamber 6212 by closing connection valve 6214. Then, in step 6412, reference chamber 6212 and control chamber 6171 are fluidly isolated from each other. In an embodiment, in step 6424, the reference chamber 6212 is connected to the vent 6226 by opening the second valve 6216. Controller 61100 holds second valve 6216 open until reference pressure sensor 6224 indicates that the reference pressure has reached ambient pressure. Alternatively, controller 61100 can control second valve 6216 to achieve a desired initial reference pressure within reference chamber 6212, as measured by reference pressure sensor 6224. Alternatively, connection valve 6214 can be closed and second valve 6216 opened before the FMS process begins. At step 6428, once the desired pressure within the reference chamber 6212 is achieved, the second valve 6216 is closed, thereby fluidically isolating the reference chamber 6212. Reference room steps 6424 and 6428 can be programmed to occur simultaneously with control room steps 6414 and 6418.

In step 6414, control chamber 6171 is pressurized to the desired pressure by opening first valve 6220 and thereby connecting control chamber 6171 to pressure source 6210. Controller 61100 monitors the pressure within control chamber 6171 with pressure sensor 6222 and controls first valve 6220 to reach a desired precharge pressure. The desired precharge pressure can be significantly greater than or significantly less than the initial reference pressure of reference chamber 6212. In one example, control chamber 6171 is precharged to a pressure approximately 40 kPa above the reference pressure for a +FMS process. In another example, control chamber 6171 is precharged to a pressure approximately 40 kPa below the reference pressure for a -FMS process. In other embodiments, the precharge pressure can be any pressure within the range of 10% to 180% of the initial reference pressure.

The controller 61100 closes the first valve 6220 in step 6418 and monitors the pressure in the control chamber 6171 with the pressure sensor 6222. The pressure within control chamber 6171 may move toward ambient pressure during step 6418 for the gas to thermally equalize with control chamber wall 6170 and membrane 6148. A large change in pressure during step 6418 may indicate an air or liquid leak that invalidates the measurement. If the rate of pressure change exceeds a predetermined acceptable rate, the two-chamber FMS process can be aborted or the calculated volume of control chamber 6171 can be discarded. After a delay from the pressurization step 6414, the rate of pressure change may be examined to allow the gas within the control chamber 6171 to approach thermal equilibrium with the boundaries 6172, 6148 of the control chamber 6171. In one example, the maximum allowable rate of pressure change during step 6418 is 12 kPA/sec. If the rate of pressure change exceeds this predetermined value, the two-chamber FMS process can be stopped and restarted. In another embodiment, the maximum allowable rate of pressure change is a function of, ie, varies based on, the calculated control chamber volume. In one example, the maximum allowable pressure change is 3 kPA/sec for a 25 ml volume and 25 kPA/sec for a 2 ml volume. In one example, the FMS process can be performed to completion regardless of the leak rate introduced to the calculated volume of control room 6171. If the measured rate of pressure change exceeds an acceptable limit for the calculated control room volume, the calculated volume can be discarded and the FMS process can be restarted.

At step 6432, control chamber 6171 and reference chamber 6212 are fluidly connected when controller 61100 opens connection valve 6214 between the two chambers. Controller 61100 monitors the pressure in each chamber with pressure sensors 6222, 6224 as the pressures in control chamber 6171 and reference chamber 6212 equalize. The controller 61100 may record the initial pressure pair and at least one pressure pair at the end of equalization at step 6432. A pressure pair refers to a signal from control pressure sensor 6222 and a signal from reference pressure sensor 6224 that are recorded at approximately the same time. Step 6432 extends from the linear period when connection valve 6214 opens to the point where the pressures in control chamber 6171 and reference chamber 6212 are approximately equal.

At step 6436, the two-chamber FMS process is completed, where the volume of control chamber 6171 is calculated using the recorded pressure pairs. Calculation of the volume of the control room 6171 will be described in detail later.

The +FMS process is schematically illustrated as a pressure versus time plot in Figure 48A. Reference numbers corresponding to the reference numbers of steps in FIG. 47 are included to indicate where those steps are shown in FIG. 48A. The pressure in control chamber 6171 is plotted as line 6302. The reference chamber pressure is plotted as line 6304. After steps 6410, 6412, 6424, 6428 of FIG. 47 are completed, the pressure versus time plot begins. At this point, the pressure within the reference chamber 6212 is at the desired reference pressure 6312. The pressure in control chamber 6171 starts at arbitrary pressure 6306 and increases to precharge pressure 6316 during step 6414. The arbitrary pressure 6306 may be the pressure in the control chamber 6171 at the end of the previous pumping operation. In another embodiment, optional pressure 6306 may be atmospheric pressure. During step 6418, control chamber pressure 6302 may decrease. At step 6432, control chamber pressure 6302 and reference chamber pressure 6304 equalize toward equilibrium pressure 6324.

- The FMS process is schematically illustrated as a pressure versus time plot in Figure 48B. The pressure in control chamber 6171 (FIG. 45) is plotted as line 6302. The pressure in reference chamber 6312 (FIG. 45) is plotted as line 6304. The horizontal time axis is divided into periods that correspond to process steps identified with the same reference numerals in FIG. The pressure versus time plot begins when the pressure in the reference chamber 6212 (line 6302 is the desired reference pressure 6312) and the pressure in the control chamber 6171 (line 6304) is the arbitrary pressure. During step 6414, the control Chamber pressure 6302 decreases to a negative precharge pressure 6317. Control chamber pressure 6302 decreases during step 6418 as the gas cooled by the rapid expansion of step 6414 is heated by control chamber walls 6172, 6148. , may increase. In step 6432, control chamber pressure 6302 and reference chamber pressure 6304 equalize toward equilibrium pressure 6324.

Polytropic + FMS Algorithm Referring now to FIG. 45, for illustrative purposes, the equalization process consists of three separate structures: a control chamber 6171, a reference chamber 6212, and a manifold passage 6204 connecting the two chambers 6171, 6212; 6205, 6207, 6209 fluid volumes. In one example, each structure has a significantly different hydraulic diameter and therefore a different level of heat transfer between the structure and the gas. In this example, reference chamber 6212 has an approximately cubic shape with a hydraulic diameter of 3.3 cm. There is very little heat transfer during the approximately 30 microsecond equalization process, and the gas within the reference chamber 6212 volume may be compressed adiabatically and can be modeled as such. In contrast, in the exemplary construction, manifold passages 6204, 6205, 6207, 6209 have a hydraulic diameter of approximately 0.2 cm, which is approximately one-fifteenth the hydraulic diameter of the reference chamber 6212 volume. Heat transfer within the manifold passages 6204, 6205, 6207, 6209 is high and gas passing through these passages 6204, 6205, 6207, 6209 is more likely to compress or expand isothermally at approximately the temperature of the manifold walls. . The hydraulic diameter of control chamber 6171 in this example has a minimum value of approximately 0.1 cm when pump chamber 6181 is full of liquid and control chamber 6171 is at its minimum volume at the end of the fill stroke. The hydraulic diameter of control chamber 6171 in this example has a maximum value of approximately 2.8 cm when pump chamber 6181 is delivering liquid and control chamber 6171 is at its maximum volume. The expansion of gas within the control chamber 6171 can be better modeled by polytropic coefficients that vary with the size of the control chamber 6171. If the control chamber 6171 volume is minimal and the expansion process is approximately isothermal, the polytropic coefficient can be set to approximately 1. If the control chamber 6171 is the largest and the expansion process is approximately adiabatic, the polytropic coefficient can be set approximately to the specific heat ratio (cp/cv), which is equal to 1.4 for air. In the case of two-chamber FMS measurements during partial stroke, the expansion process occurs with significant heat transfer, which is not sufficient to be isothermal. For measurements during partial strokes, the polytropic coefficient can be set to a value between 1 and 1.4. Since the volume of the control room 6171 is an unknown quantity for this analysis, the polytropic coefficient for the control room 6171 can be based on an estimate of the control room 6171 volume.

Referring now to FIG. 49A, the gases in the control chamber 6510, reference chamber 6520 and manifold lines 6530, 6531 structure do not mix through the structure 6510, 6520, 6530, 6531, but expand, contract and move 3 can be modeled as three gas masses 6512, 6532, 6522. Conceptually, for modeling purposes, each of these masses 6512, 6532, 6522 is a closed system that can move, change size, and exchange energy with structure; They cannot enter or exit a closed system. Closed system models are well-understood concepts in thermodynamics and fluid mechanics. These masses may also be referred to as control room system 5612, reference room system 6522, and manifold or interconnect line system 6532.

Based on the thermodynamic model of the three masses 6512, 6532, 6522, the volume of the control chamber 6510 can be calculated from the measured pressures of the control chamber 6510 and the reference chamber 6520. Control room mass or gas 6512 is the gas that occupies control room 6510 at the end of the equalization process. Reference chamber gas 6522 is the gas that occupies reference chamber 6520 at the beginning of the equalization process. Manifold gas 6532 satisfies the structural equilibrium between control room gas 6512 and reference chamber gas 6522, including the connecting conduit between the control room gas and the reference chamber.

The volumes and temperatures of the three closed systems 6512, 6532, 6522 can then be calculated from the initial conditions, pressure pairs, heat transfer assumptions, and constant total volume constraints for the three closed systems. Pressure equalization can be modeled by using different polytropic coefficients for each volume 6510, 6520, 6530, 6531 to capture the relative importance of heat transfer in each. The ideal gas and polytropic process equations for the three systems 6512, 6532, 6522 can be combined and arranged to calculate the volume of the control room 6510. The following paragraphs describe one or more sets of equations that enable calculation of the control chamber 6510 volume based on the pressure measured during the pressure equalization step of the FMS process (see 6432 in FIGS. 47 and 108A). Describe the derivation.

Illustration of Closed Systems for +FMS The upper image in Figure 49A presents the positions of the three closed systems 6512, 6532, 6522 at the beginning of pressure equalization in the +FMS process. The lower image presents the positions of the three closed systems 6512, 6532, 6522 at the end of pressure equalization. During the equalization process, the position of the closed system 6512, 6532, 6522 is between the two extreme values presented in Figure 49A. As an example, neither control room system 6512 nor reference room system 6522 satisfy their respective structures. The following paragraphs present the closed systems 6512, 6532, 6522 in more detail.

Control chamber gas system 6512 is the gas that fills control chamber 6510 after pressure equalization. Prior to pressure equalization, the control chamber gas system 6512 is compressed to a precharge pressure that is higher than the final equalization pressure and therefore does not occupy the entire control chamber 6510. The control room gas system 6512 can be modeled as expanding in a polytropic process during pressure equalization of the +FMS process, where pressure and volume are related by the following equation:

p _f V _cc ^nCC = constant where p _f is the equalized pressure, V _cc is the volume of the control chamber 6510, and nCC is the polytropic coefficient for the control chamber 6510.

Reference gas system 6522 is the gas that occupies the entire reference volume 6520 before equalization. Reference gas system 6522 is compressed as the higher pressure gas in control chamber 6510 expands and forces manifold gas system 6532 into reference chamber 6520. In one example shown in FIG. 36, the reference chamber (shown as 174 in FIG. 36) is sufficiently open or internal so that the compression or expansion processes during pressure equalization can be modeled as adiabatic. There are no features/elements. In this case, the polytropic coefficient (n) can be set approximately equal to the specific heat ratio of the gas present in the chamber. The pressure and volume of reference chamber gas 6522 are related by the following equation.

p _R0 V _Ref ^nR = constant where p _R0 is the initial reference pressure, V _Ref is the volume of the reference chamber, and nR is the specific heat ratio to the gas in the reference chamber (nR=1.4 air). In another example, if the chamber 6520 is at least partially filled with a heat absorbing material, such as open cell foam, wire mesh, particles, etc. that provides near-isothermal expansion, the polytropic coefficient (nR) relative to the reference chamber is It may have a value of approximately 1.0.

In the +FMS process, the conduit or manifold gas system 6532 occupies the entire volume of the interconnect volumes 6530, 6531 and a portion 6534 of the control room 6510 prior to equalization. After equalization, conduit gas system 6532 occupies a portion of interconnect volumes 6530, 6531 and reference volume 6520. The portion of the conduit gas system 6532 that resides on the control room side of the valve 6540 of the interconnect volume 6530 is designated herein as 6533. The portion of the conduit gas system 6532 that resides on the reference chamber side of the valve 6540 of the interconnecting volume 6531 is designated 6535. The portion of conduit gas system 6532 that exists within control room 6510 prior to equalization is designated herein as 6534. The portion of conduit gas system 6532 that exists within reference chamber 6520 after equalization is designated 6536.

In one example, interconnecting volumes 6530 and 6531 may be narrow passageways that provide high heat transfer and that allow the conduit gas system 6532 within volumes 6530 and 6531 to reach the temperature of the solid boundaries or walls of the passageways. ensure that it is close to The temperature of the interconnect volume 6530, 6531 or the structure surrounding the manifold passageway is referred to herein as the wall temperature (T _w ). In another example, the temperature of the conduit gas system 6532 within volumes 6530, 6531 is, in part, a function of wall temperature. Portions of the conduit or manifold gas system within the control room 6534 may be modeled at the same temperature as the control room gas system 6512. The control room portion of the conduit gas system 6534 can be considered to expand in the same manner as the control room gas system 6512 and have the same temperature as the control room gas system 6512. Portions of the line or manifold gas system within reference chamber 6536 can be modeled by a temperature that is, in part, a function of wall temperature. In another example, the reference chamber portion of the conduit gas system 6536 can be modeled as not thermally interacting with the boundaries of the reference chamber 6520 such that the temperature of the conduit gas system portion 6536 is equal to the wall temperature and reference chamber 6520 pressure.

The formulas in this section use the following nomenclature.
Variable γ: Specific heat ratio n: Polytropic coefficient p: Pressure V: Volume T: Temperature Superscript:
n: polytropic coefficient nCC: polytropic coefficient for the control room nR: polytropic coefficient for the reference room Subscript:
c: Control room system CC: Physical control room f: Value at the end of equalization i: i-th value IC: Physical interconnection volume or manifold passage IC_R: Physical interconnection volume on the reference chamber side of the valve IC_CC : physical interconnection volume on the control room side of the valve l: line or interconnection/manifold system 0: value at the start of equalization pmp: pump r: reference system Ref: physical reference chamber w: wall of the interconnection volume

The equation for control room 6510 can be understood from the conceptual model of the three separate mass systems in FIG. It can be derived as follows. This relationship can be expressed as the sum of the volume changes of each closed system 6512, 6522, 6532 that are zero for each i-th set of values from the beginning to the end of pressure equalization as follows:
0 = volumetric change in control room mass + volumetric change in interconnection mass + volumetric change in reference chamber mass 0 = ΔV _ci + ΔV _ri + ΔV _li (13)
In the formula, the i-th value of ΔV _ci , ΔV _ri , and ΔV _li represents these values at the same point in time. Based on polytropic processes and ideal gas law pressure/volume relationships, the volume change in the control room gas system (ΔV _ci ), the volume change in the reference gas system (ΔV _ri ), and the volume change in the conduit gas system (ΔV _li ) are On the other hand, the expression can be expanded. The equation for the ith volume change of control room gas system 6512 is equal to the ith volume of control room mass 6512 minus the volume of control room mass 6512 at the beginning of equalization. The volume of the control room mass 6512 at time i is the volume of the control room 6510 raised to the power of the ratio of the final control room 6510 pressure to the control room 6510 pressure at time i by 1/the polytropic coefficient of the control room 6510, as follows: It is calculated by multiplying the values.
Change in current volume of control room mass = Current volume of control room mass - Initial volume of control room mass

The expression for the reference gas system volume change (ΔV _r ) is derived from the pressure/volume relationship for a polytropic process. The equation for the ith mass change of reference chamber gas system 6522 is equal to the ith volume of reference chamber mass 6522 minus the volume of reference chamber mass 6522 at the beginning of equalization. The volume of the reference chamber mass 6520 at time i is the structural volume of the reference chamber 6520 plus the ratio of the initial reference chamber 6520 pressure to the reference chamber 6520 pressure at time i as 1/the polytropic coefficient of the reference chamber 6520. It is calculated by multiplying the value raised to the power.
Change in current volume of reference chamber mass = Current volume of reference chamber mass - Initial volume of reference chamber mass

The expression for the volume change (ΔV _l ) of the interconnect gas system 6532 is derived from a constant mass gas of the system (V*ρ=constant). The equation for the ith volume change of conduit gas system 6532 is equal to the current mass of the system minus the initial volume of interconnect gas system 6532. The current volume of the interconnect or line gas system 6532 is the initial mass multiplied by the ratio of the initial density to the current density of the system. The initial volume of interconnect gas system 6532 is the sum of volumes 6534, 6533, and 6535 depicted in the upper image of FIG. 49A as follows:
Current volume change of interconnect mass = Current volume of interconnect mass + Initial volume of interconnect mass

The density terms ρ _l0 , ρ _li are the average densities of the gases in the conduit gas system at the beginning of equalization and at any point i during equalization. Conduit gas system 6532 includes gases at different temperatures and pressures. Conduit gas system 6532 includes gas in a volume within control chamber 6510 in a volume labeled 6534, gas in a manifold passage on the control chamber side of valve 6540, labeled 6533, and gas in a manifold passage labeled 6535. The gas in the manifold passage on the reference chamber side of valve 6540, which is located in the valve 6540, and the gas in the reference chamber labeled 6536.

Combining these four equations, we get the pair of measured pressures at the beginning of pressure equalization (P _CC0 , P _Ref0 ) and the measured pressure at any point during the equalization: (P _CCi , P _Refi ), the control chamber 6510 pressure at approximately the end of equalization (P _CCf ), and the constant volume of the reference chamber (V _Ref ) and interconnect volume (V _IC ) as a function of An expression for the volume of control room 6510 (V _CC ) can be developed.

where the densities (ρ _l0 , ρ _li ) of the manifold or line system 6532, along with the associated temperatures as described below, are expressed as the initial pressure pairs (P _CC0 , P _Ref0 ) and any pressure pairs during equalization (P _CCi , P _Refi ).

The density of the conduit gas system (ρ _l0 , ρ _li ) in equation (16) is calculated from the volume-weighted average density for each physical volume (i.e., control room 6510, reference room 6520, and interconnected volumes 6530, 6531). can be calculated.

where R is the universal gas constant for air, and the temperatures T _{IC_CC} , T _{IC_R} , T _lr may be, in part, a function of the interconnect volume wall temperature. In another example, the temperatures T _{IC_CC} , T _{IC_R} , T _lr may be a function in part of the interconnect volume wall temperature and the control room gas temperature (T _CCi ). In another example, temperatures T _{IC_CC} , T _{IC_R} , T _lr may be interconnect wall temperatures (T _w ). In another example, the temperature may be a control room temperature (T _CCi ). The value of ΔV _ri is calculated from equation (14). The value of ΔV _cf −ΔV _ci is 6534 volumes and is calculated as follows.

The density of the conduit gas system 6532 before pressure equalization is calculated from a formula similar to (18), which is the volume-weighted average density for each physical volume (i.e., control room 6510 and interconnected volumes 6530, 6531). be able to.

The change in control room gas system volume (ΔV _cf ) used in equation (18) is calculated from the quantity 1 to the physical volume of the control room 6510 as follows: is calculated by multiplying by the value obtained by subtracting the value obtained by multiplying 1/the polytropic coefficient of the control room.

By assuming a constant temperature for the conduit gas system 6532 such that the density ratio (ρ _l0 /ρ _lf ) is equal to the pressure ratio (P _l0 /P _lf ), an estimate of the control room 6510 volume can be derived. . To further simplify the estimation, the specific heat ratio γ) is used instead of the polytropic coefficient. In this more simplified equation, the control chamber 6510 volume is the measured pressure pair at the beginning of pressure equalization (P _CC0 , P _Ref0 ) and the measured pressure pair at the end of equalization (P _CCf , P _Ref ) and the constant volume of the reference chamber (V _Ref ) and the interconnect volume (V _IC ).

The gases in the three closed systems 6512, 6522, 6532 can be modeled as ideal gases, so the temperature can be determined from the initial conditions and new pressure or volume as follows.

The initial temperature of the gas in the control chamber (T _CC0 ) can be calculated from the interconnect volume wall temperature, the precharge pressure 6316 (FIG. 108A), and the pressure 6306 in the control chamber 6510 just before precharging. . The compression of the gas in the control volume to the precharge pressure can be modeled as a polytropic process and using the ideal gas law in equation (23). The control chamber 6510 pressure 6306 before precharging is referred to herein as pumping pressure (Ppmp).

The temperature of the gas in the control chamber 6510 at the i-th step during expansion (T _CCi ) is determined by the initial control chamber 6510 temperature and precharge pressure 6316 (FIG. 108A) using equation (23) as follows. , i-th control chamber 6510 pressure (P _CCi ).

The value of the polytropic coefficient (nCC) for the control room gas system used in Equations 14, 17, 19, 21, 25 varies with the volume of the control room 6510, from approximately 1 for small volumes to approximately the specific heat ratio for large volumes. It can be in the range of The specific heat ratio of air and other systems of mainly diatomic molecules is 1.4. In one example, the value of nCC (for +FMS) can be expressed as a function of the estimated control room volume (Equation 22) as follows:

nCC=1.4-3.419× ^10-5 (23.56-V _CCEst ) ^3.074 (26)
A method for determining the relationship between control room volume (V _CC ) and polytropic coefficient (nCC) is described in the following section.

Polytropic-FMS Algorithm The -FMS algorithm, similar to the +FMS algorithm described above, can be developed to calculate the volume of control chamber 6171 in FIG. 45 from the pressures of control chamber 6171 and reference chamber 6212 for the -FMS process. - In the FMS process, the first chamber (eg 6171) is precharged to a lower pressure than the known second chamber (eg 6212).

Referring now to FIG. 49B, the gases within the control chamber 6510, reference chamber 6520 and manifold lines 6530, 6531 structure do not mix through the structure 6510, 6520, 6530, 6531, but expand, contract and move 3 can be modeled as three gas masses 6512, 6532, 6522. Based on the thermodynamic model of the three masses 6512, 6522, 6532, the volume of the control chamber 6510 can be calculated from the measured pressures of the control chamber 6510 and the reference chamber 6520. - In the FMS algorithm, the control room mass 6512 is the gas that occupies the control room 6510 at the beginning of the equalization process. Reference chamber mass 6522 is the gas that occupies reference chamber 6520 at the end of the equalization process. Manifold gas 6532 satisfies the structural equilibrium between control chamber gas 6512 and reference chamber gas 6522, including the connecting conduit between the control and reference chambers.

The volumes and temperatures of the three conceptual closed systems 6512, 6532, 6522 can then be calculated from the initial conditions, pressure vs. heat transfer assumptions and constant total volume constraints for the three closed systems 6512, 6532, 6522. . Pressure equalization can be modeled by using different polytropic coefficients for each volume 6510, 6520, 6530, 6531 to capture the relative importance of heat transfer in each. The constant mass, ideal gas, and polytropic process equations for the three systems 6512, 6522, 6532 can be combined and arranged to calculate the volume of the control room 6510. The following paragraphs describe the derivation of one or more sets of equations that allow calculation of the control chamber 6510 volume based on the pressure measured during the pressure equalization step of the -FMS process.

- Illustration of closed systems for FMS The upper image in figure 49B presents the position of the three closed systems 6512, 6522, 6532 at the beginning of pressure equalization in the -FMS process. The lower image presents the positions of the three closed systems 6512, 6522, 6532 at the end of pressure equalization. During the equalization process, the position of the closed system 6512, 6522, 6532 is between the two extreme values presented in Figure 49B. As an example, neither control room system 6512 nor reference room system 6522 satisfy their respective structures. The following paragraphs present closed systems in more detail.

- The control room gas system 6512 in the FMS algorithm is the gas that fills the control room 6510 before pressure equalization. During pressure equalization, the higher pressure reference chamber gas system 6522 expands first and as it forces the manifold gas system 6532 into the control chamber 6510, the control chamber gas system 6512 is compressed. The control room gas system 6512 can be modeled by polytropic compression during pressure equalization of the -FMS process, where pressure and volume are related by the following equation:

p ₀ V _cc ^nCC = constant where p ₀ is the initial pressure in the control chamber 6510, V _cc is the volume of the control chamber 6510, and nCC is the polytropic coefficient for the control chamber 6510.

- The reference gas system 6522 in the FMS algorithm is the gas that occupies the entire reference volume 6520 after equalization. Reference gas system 6522 expands during equalization as higher pressure gas in reference chamber 6520 forces manifold gas system 6532 out of reference chamber 6520 and toward control chamber 6510. In one example shown in FIG. 36, the reference chamber (labeled 174 in FIG. 36) is sufficiently open or There are no internal features/elements, so the polytropic coefficient (nR) can be set approximately equal to the specific heat ratio of the gas present within the chamber. The pressure and volume of reference chamber gas 6522 are related by the following equation.

p _R0 V _Ref ^nR = constant where p _R0 is the initial reference pressure, V _Ref is the volume of the reference chamber, and nR is the specific heat ratio relative to the reference chamber (nR=1.4 air). In another example, if the reference chamber 6520 is filled with a heat absorbing material such as open cell foam, wire mesh, particles, etc. that provides near-isothermal expansion, the polytropic coefficient (nR) for the reference chamber is approximately 1. It may have a value of 0.

- In the FMS process, the conduit or manifold gas system 6532 occupies the entire volume of the interconnecting volumes 6530, 6531 and part 6536 of the reference chamber 6520 before equalization. After equalization, conduit gas system 6532 occupies interconnect volumes 6530, 6531 and a portion 6534 of control room 6510. The portion of the conduit gas system 6532 that resides on the control room side of the valve 6540 of the interconnect volume 6530 is designated herein as 6533. The portion of the conduit gas system 6532 that resides on the reference chamber side of the valve 6540 of the interconnecting volume 6531 is designated 6535. The portion of conduit gas system 6532 that resides within control room 6510 is designated herein as 6534. The portion of conduit gas system 6532 that resides within reference chamber 6520 is designated 6536.

In one example, interconnecting volumes 6530 and 6531 may be narrow passageways that provide high heat transfer and allow conduit gas systems 6532 within volumes 6530 and 6531 to reach the temperature of the solid boundaries or walls of the passageways. Make sure it's close. The temperature of the interconnect volume 6530, 6531 or the structure surrounding the manifold passageway is referred to herein as the wall temperature (T _w ). In another example, the temperature of the conduit gas system 6532 within volumes 6530, 6531 is in part a function of wall temperature. The portion of the conduit gas system within the control room 6534 may be modeled at the same temperature as the control room gas system 6512. The control room portion of the conduit gas system 6534 can be considered to expand in the same manner as the control room gas system 6512 and have the same temperature as the control room gas system 6512. Portions of the line or manifold gas system within reference chamber 6536 can be modeled by a temperature that is, in part, a function of wall temperature. In another example, the reference chamber portion of the conduit gas system 6536 can be modeled as not thermally interacting with the boundaries of the reference chamber 6520 such that the temperature of the conduit gas system portion 6536 in the reference chamber is , is a function of wall temperature and reference chamber 6520 pressure.

The formulas in this section use the following nomenclature.
Variable γ: Specific heat ratio n: Polytropic coefficient p: Pressure V: Volume T: Temperature Superscript:
n: polytropic coefficient nCC: polytropic coefficient for the control room nR: polytropic coefficient for the reference room Subscript:
c: Control room system CC: Physical control room f: Value at the end of equalization i: i-th value IC: Physical interconnection volume or manifold passage IC_R: Physical interconnection volume on the reference chamber side of the valve IC_CC : Physical interconnection volume on the control room side of the valve l: Line or manifold/interconnection system 0: Value at the start of equalization pmp: Pump r: Reference system Ref: Physical reference room w: Wall of the interconnection volume temperature

The equation for control room 6510 is derived from the conceptual model of the three separate mass systems in FIG. can be derived. This relationship can be expressed as the sum of the volume changes of each closed system 6512, 6522, 6532 that are zero for each i-th set of values from the beginning to the end of pressure equalization as follows:
0 = volumetric change in control room mass + volumetric change in interconnection mass + volumetric change in reference chamber mass 0 = ΔV _ci + ΔV _ri + ΔV _li (13)
In the formula, the i-th value of ΔV _ci , ΔV _ri , and ΔV _li represents these values at the same point in time. Based on polytropic processes and ideal gas law pressure/volume relationships, the volume change in the control room gas system (ΔV _ci ), the volume change in the reference gas system (ΔV _ri ), and the volume change in the conduit gas system (ΔV _li ) are On the other hand, the expression can be expanded. The equation for the ith volume change of control room gas system 6512 is equal to the ith volume of control room mass 6512 minus the volume of control room mass 6512 at the beginning of equalization. The volume of the control room mass 6512 at time i is the volume of the control room 6510 raised to the power of the ratio of the final control room 6510 pressure to the control room 6510 pressure at time i by 1/the polytropic coefficient of the control room 6510, as follows: It is calculated by multiplying the values.
Change in current volume of control room mass = Current volume of control room mass - Initial volume of control room mass

The expression for the reference gas system volume change (ΔV _r ) is derived from the pressure/volume relationship for a polytropic process. The equation for the ith mass change of reference chamber gas system 6522 is equal to the ith volume of reference chamber mass 6522 minus the volume of reference chamber mass 6522 at the beginning of equalization. The volume of the reference chamber mass 6520 at time i is the structural volume of the reference chamber 6520 plus the ratio of the initial reference chamber 6520 pressure to the reference chamber 6520 pressure at time i as 1/the polytropic coefficient of the reference chamber 6520. It is calculated by multiplying the value raised to the power.
Change in current volume of reference chamber mass = Current volume of reference chamber mass + Initial volume of reference chamber mass

The expression for the volume change (ΔV _l ) of the interconnect gas system 6532 is derived from a constant mass gas of the system (V*ρ=constant). The equation for the ith mass change of conduit or manifold gas system 6532 is equal to the current mass of system 6532 minus the initial mass of system 6532. The current mass of interconnect or manifold gas system 6532 is the initial mass multiplied by the ratio of the initial density to the current density of system 6532. The initial volume of interconnect gas system 6532 is the sum of volumes 6534, 6533, and 6535 depicted in FIG. 49B as follows:
Current volume change of interconnect mass = Current volume of interconnect mass + Initial volume of interconnect mass

The density terms ρ _l0 , ρ _li are the average densities of the gases in the conduit gas system at the beginning of equalization and at any point i during equalization. Conduit gas system 6532 includes gases at different temperatures and pressures. Conduit gas system 6532 includes gas in a volume within control chamber 6510 in a volume labeled 6534, gas in a manifold passage on the control chamber side of valve 6540, labeled 6533, and gas in a manifold passage labeled 6535. This includes the gas in the manifold passage on the reference chamber side of valve 6540, which is located in the valve 6540, and the gas in the reference chamber labeled 6536.

Combining these four equations, we get the pair of measured pressures at the beginning of pressure equalization (P _CC0 , P _Ref0 ) and the measured pressure at any point during the equalization: (P _CCi , P _Refi ), the reference chamber 6520 pressure at approximately the end of equalization (P _Reff ), and the constant volume of the reference chamber (V _Ref ) and the interconnect volume (V _IC ). , an expression can be developed for the volume of the control room 6510 (V _CC ).

(30)

(30)

where the density of the line system 6532 (ρ _l0 , ρ _li ), along with the associated temperature as described below, is the initial pressure pair (P _CC0 , P _Ref0 ) and any pressure pair during equalization (P _CCi , P _Refi ).

The density of the conduit gas system (ρ _l0 , ρ _li ) in Equation (29) is calculated from the volume-weighted average density for each physical volume (i.e., control room 6510, reference room 6520, and interconnected volumes 6530, 6531). can be calculated.

where R is the universal gas constant for air, and the temperatures T _{IC_CC} , T _{IC_R} , T _1C may be a function in part of the interconnect volume wall temperature. In another example, the temperatures T _{IC_CC} , T _{IC_R} , T _lCr may be a function in part of the interconnect volume wall temperature and the reference chamber gas temperature (T _Refi ). In another example, temperatures T _{IC_CC} , T _{IC_R} , T _1C may be interconnect wall temperatures (T _w ). In another example, the temperature may be a reference room temperature (T _Refi ).

The value of ΔV _cf for equation (31) is calculated from equation (27), where the final control chamber pressure (P _CCf ) is used for P _CCi and V _CCEst is used for V _CC . The value of ΔV _ri for equation (31) is calculated from equation (28).

The density of the conduit gas system 6532 before pressure equalization is calculated from a formula similar to equation (31), which is the volume-weighted average density for each physical volume (i.e., control room 6510 and interconnect volumes 6530, 6531). can do.

Derive an estimate of the control room 6510 volume by assuming a constant temperature for the conduit or manifold gas system 6532 such that the density ratio (ρ _l0 /ρ _lf ) is equal to the pressure ratio (P _l0 /P _lf ). Can be done. To further simplify the estimation, the specific heat ratio (γ) is used instead of the polytropic coefficient. In this more simplified equation, the volume of the control chamber (V _CC ) in the -FMS process is determined by the three pressures (i.e. the measured pressure pair at the beginning of pressure equalization (P _CC0 , P _Ref0 ) and the single function of the constant volume of the reference chamber (V _Ref ) and interconnected volume (V _IC ) with the equalized pressure (P _f )) of the polytropic coefficient for the reference chamber (nR) and the polytropic coefficient for the control room (nCC) It can be expressed as

The gases in the three closed systems 6512, 6522, 6532 can be modeled as ideal gases, so the temperature can be determined from the initial conditions and new pressure or volume as follows.

The initial temperature of the gas in the control chamber (T _CC0 ) is determined by the temperature of the interconnect volume wall, the precharge pressure 6316 (FIG. 108B), and the pressure 6306 in the control chamber 6510 just before precharging (see FIG. 108B). can be modeled as a polytropic process and using the ideal gas law in equation (23). The control chamber pressure 6306 before precharging is referred to herein as pumping pressure (Ppmp).

The value of the polytropic coefficient (nCC) for a control room gas system varies with the volume of the control room 6510 and can range from approximately 1 for small volumes to approximately the specific heat ratio for large volumes. The specific heat ratio of air and other systems of predominantly diatomic molecules is 1.4. In one example, the value of nCC for -FMS can be expressed as a function of the estimated control room volume (Equation 21) as follows:

nCC=1.507-1.5512× ^10-5 (23.56-V _CCEst ) ^3.4255 (34)
A method for determining the relationship between control room volume (V _CC ) and polytropic coefficient (nCC) is described in the following section.

Determining the polytropic coefficient n _CC The value of the polytropic coefficient n _CC can be determined empirically or analytically. In a possible understanding, the polytropic coefficient compares the possible temperature of a gas due to heat transfer with a structure to the temperature change caused by a pressure change. The value of the polytropic coefficient can vary depending on the pressure change, the rate of pressure change, and the shape and size of the gas volume.

In one embodiment, the polytropic coefficient n _CC is determined by generating the control chamber 6171 (FIG. 45) with a known volume and running a +FMS or -FMS process to determine the pressure in the control and reference chambers during equalization. It can be determined experimentally by recording the The polytropic+FMS algorithm, including equations (17), (18), and (20), uses a set of pressure measurements and a known control room volume (V _CC ) to solve for the value of the polytropic coefficient (n _CC ) for the control room. Applies to. This process of determining polytropic coefficients was performed for several different volumes ranging from 1.28 ml, typical of the control chamber 6171 after the fill stroke, to 23.56 ml, typical of the control chamber 6171 after the delivery stroke. repeated. To improve the accuracy of determining the n _CC , the FMS process can be repeated several times for each volume. An example of this experimental determination for the +FMS process is shown in Figure 50A, where for the estimated volume of the control room (V _CCEst ), as calculated by equation (22) for six different volumes, , n _CC values are plotted. An exponential equation was fitted to the data to generate equation (26) representing the polytropic coefficient for the estimated volumetric control room. The plot in FIG. 50A plots the values 1.4-n _CC versus 23.56-V _CCEst in order to better fit the data with a simple formula.

Similarly, the polytropic coefficient (n _CC ) for -FMS can be determined by applying the -FMS process to a known control room volume and recording the control and reference chamber pressures during equalization. The polytropic-FMS algorithm, including equations (30), (31), and (32), uses a set of pressure measurements and a known control room volume (V _CC ) to solve for the value of the polytropic coefficient (n _CC ) for the control room. ) applies to This process of determining polytropic coefficients was repeated for several different volumes. - An example of the resulting values for n _CC for the FMS process is shown in Figure 50B, where the estimated volume of the control room (V _CCEst ) versus the value of n _CC . An exponential equation was fitted to the data to generate equation (34) representing the polytropic coefficient (n _CC ) with respect to the estimated volume control room (V _CCEst ). The plot in FIG. 50B plots the values 1.507-n _CC versus 23.56-V _CCEst in order to better fit the data with a simple formula.

In one embodiment, a constant, known control room volume is created by attaching a machined volume to the front of the mounting plate 170 (FIG. 92), such that the machined volume is sealed to the mounting plate. 173C, which connects the control chamber to a pressure source and pressure sensor.

Polytropic FMS Calibration Procedure for V _CC Referring now to FIGS. 51 and 52, a flowchart is presented for calculating control room volume from pressure data recorded during a two-chamber FMS process and polytropic FMS algorithm. The flowchart of FIG. 39 presents a relatively simple process in which minimal pressure data is required to calculate the volume of the control chamber (V _CC ). The flowchart of FIG. 52 describes a more complex calculation that more accurately calculates the volume of the control chamber (V _CC ), requiring multiple pressure pairs during the equalization process.

The simple polytropic FMS calculation procedure presented in FIG. Starting at step 6400, the method includes storing in memory. In step 6614, the controller analyzes the plurality of pressure pairs to identify an initial control chamber pressure (P _CC0 ) and an initial reference pressure (P _Ref0 ) as the control chamber pressure and reference pressure when the equalization process begins. . The method or procedure for identifying the onset or initial pressure of equalization is described in the previous section entitled Pump Delivery Volume Measurement, where the initial control chamber pressure and reference chamber pressure are referred to as Pd and Pr. . In step 6618, the controller analyzes the plurality of pressure pairs to determine when the control chamber pressure and the reference chamber pressure are approximately equalized or changing at a sufficiently low rate, the final control chamber pressure (P _CCf ) and Identify the final reference pressure (P _Ref ). One or more methods for determining when the control chamber pressure and reference chamber pressure have approximately equalized are described in the previous section entitled Pump Delivery Volume Measurement.

Alternatively, steps 6614 and 6618 may occur during the FMS process 6400 to identify initial and final pressures for the control and reference chambers. The controller or FPGA processor can identify the initial and final pressures and store only those values. In one example, the initial pressure can be the control chamber pressure and the reference pressure when the connecting valve opens, and the final pressure is when the second valve opens to vent the reference and control chambers after equalization. control room pressure and reference pressure.

In step 6620, the volume of the control chamber is estimated from the initial pressure and final pressure using equation (22) for a +FMS process and equation (34) for -FMS. In step 6641, for a +FMS process, the polytropic coefficient (n _CC ) for the control room is calculated using the resulting estimate of the control room volume (V _CCEst ) in equation (26). This polytropic value (n _CC ) and estimated volume (V _CCEst ), together with the initial and final pressure pairs, are fed into equations (17), (18), (19) for the +FMS process and are The volume (V _CC ) is calculated. - For the FMS process, in step 6641, the polytropic coefficient (n _CC ) is calculated using equation 34, and the control room volume (V _CC ) is calculated using equations (30), (31), (32). Ru.

A processor, such as controller 61100 in FIG. 45, may perform steps 6614-6618 (FIG. 51) on the stored pressure pairs. In an alternative embodiment, processor 61100 may perform steps 6614 and 6618 without storing the pressure pairs during pressure equalization.

FIG. 52 describes a more complex calculation of control room volume (V _CC ). Calculate FMS 6400, identify initial control chamber pressure (P _CC0 ) and reference chamber pressure (P _Ref0 ) 6614, determine final control chamber pressure (P _CCf ) and final reference chamber pressure (P _Ref ) 6618, and control The initial steps to estimate the chamber volume (V _CCEst ) 6620 are the same as described above with respect to FIG. 51 .

Steps 6624, 6628, 6630, and 6640 are similar to the calculation steps described above in the section entitled Pump Delivery Volume Measurement, except that the calculation of control chamber volume (V _CC ) is performed using equation (17), ( 18) and (19), and the -FMS process is different in that it is based on equations (30), (31), and (32). In step 6624, the pressure pair of control chamber pressure (P _CCi ) and reference chamber pressure (P _ri ) is correlated with the previous subsequent pressure pair by interpolation to obtain the exactly simultaneously occurring pressure pair (P _CCi ^* , P _ri ^* ) is calculated. In other embodiments, step 6624 is skipped and subsequent calculations use the uncorrected pressure pair (P _CCi , P _ri ). At step 6628, the control chamber volume (V _CC ) is calculated for each pressure pair. In steps 6630, 6640, the optimization algorithm described in the section entitled Pump Delivery Volume Measurement is performed to determine the optimal final pressure pair (P _CCf , _PReff ) and resulting control chamber volume (V _CC ). .

In an alternative embodiment, the calculations described in FIGS. 51 and 52 may be performed in a processor separate from controller 61100 in FIG. The calculations can be performed, for example, in an FPGA, which also processes input and output signals from actuators, valves and pressure sensors.

Air Detection with Polytropic FMS Algorithm Referring now to FIG. 43, another aspect of the present invention involves determining the presence of air within pump chamber 181 and, if present, the volume of air present. Such determination may be useful, for example, to ensure that a priming procedure is performed properly to remove air from the cassette 24, and/or to help ensure that no air is delivered to the patient. , potentially important. In some embodiments, for example, when delivering fluid to a patient through the lower opening 187 at the bottom of the pump chamber 181, air or other gases trapped in the pump chamber tend to remain within the pump chamber 181. Unless the volume of gas is greater than the effective dead space volume of the pump chamber 181, it is prevented from being pumped to the patient. As discussed below, in accordance with aspects of the present invention, the volume of air or other gas contained within pump chamber 181 may be determined before the volume of gas becomes greater than the volume of effective dead space in pump chamber 181. Then, gas can be purged from the pump chamber 181.

At the end of the filling stroke, a determination of the amount of air in the pump chamber 181 can be made, and thus it can be done without disturbing the pumping process. For example, at the end of the fill throat talk, membrane 15 and pump control area 1482 are pulled away from cassette 24 such that membrane 15/area 1482 contacts the wall of control chamber 171B. The +FMS procedure as described in FIG. 47 can be performed to measure pressure equalization and calculate the apparent volume of control room 171 (FIG. 34), as described above. However, away from the membrane gas pacer 50, the +FMS procedure after the fill stroke also measures the volume of any gas or bubbles on the liquid side of the membrane 15.

The volume of the control chamber when the membrane 15 is in contact with the control chamber wall 172 is generally known based on the design and manufacturing process. This minimum control room volume is V _CCFix . The control chamber volume measured during the +FMS procedure at the end of the fill command is V _{CC +} . If the measured control room volume (V _CC+ ) is greater than V _CCFix , control system 66 or controller 1100 may command a -FMS procedure to calculate the control room volume (V _CC- ). - If the FMS procedure gives substantially the same control room volume as +FMS, the controller can recognize that the fill line is occluded. Alternatively, if the -FMS procedure produces a smaller control room volume, the controller recognizes the difference as the sum size of the bubbles (V _AB ) as follows.

V _AB =V _CC+ -V _CC- (30)
A similar method can be used at the end of the delivery stroke when the membrane 15 is in contact with the gas pacer 50. The +FMS procedure does not measure the volume of air in the liquid when in contact with the membrane 15 gas pacer 50, but only the volume of air within the control chamber 171. However, the -FMS procedure pulls the membrane away from the spacer 50 and measures the volume of air on the dry side (ie, control chamber 171) and liquid side (pump chamber 181) of the membrane 15. Therefore, at the end of the delivery stroke, the volume of air in the liquid ( _VAB ) can also be determined.
V _AB =V _CC- -V _CC+ (31)

Air Calibration Further aspects of the present disclosure include methods of calibrating -FMS and +FMS processes by direct measurement of control chamber volume 6171 (FIG. 45) using pressure measurements independent of pressure measurements associated with the FMS process. . This method of calibrating a two-chamber FMS process is referred to herein as the air calibration method. References to hardware in this section are directed to FIG. 45, but apply equally to other pneumatically actuated diaphragm pumps with equivalent hardware components. The air calibration method improves the accuracy of the two-chamber FMS method over the entire range of control room volumes, including, but not limited to, the nominal volume (V _Ref ) relative to the reference chamber 6212 and the volumes of the interconnect volumes 6204, 6205, 6207, 6209. (V _IC ). The method also allows compensation for differences between the actual and nominal volumes of the reference chamber 6212 and interconnect volumes 6204, 6205, 6207, 6209. The method also compensates for differences between actual and assumed heat transfer in various volumes of the two-chamber FMS hardware, including control room 6171, reference room 6212, and interconnect volumes 6204, 6205, 6207, 6209. enable.

The air calibration method combines control chamber 6171 pressure measurements with measurements of displaced liquid to determine the number of membranes 6148 between when contacting control chamber wall 6172 and when contacting spacer 650 of cassette 624. At the position, the volume of the control room 6171 is measured. These measurements of control room volume (VCIso) are compared to FMS calibration values for control room volumes (VFMSi) to calculate calibration coefficients (CCali) for each calculated FMS volume (VFMSi). A calibration formula can then be fitted to the plot of CCali values versus VFMSi values. The calibration formula can then be used to improve the accuracy of control room volume calculations. The air calibration method can be applied to both +FMS and -FMS processes, resulting in separate calibration equations for each.

Air Calibration for +FMS Flowchart 6700 in FIG. 53B describes an example of an air calibration method. The hardware setup for air calibration includes a liquid-primed pneumatically driven pump and an outlet plumbed to a scale or graduated cylinder. The hardware setup also includes two-chamber FMS hardware, such as a control volume or chamber 6171, pressure sensors 6222, 6224, multiple valves 6214, 6220, and a reference volume or chamber 6212. Also included is a controller 61100 that commands pneumatic valves 6214, 6220, records pressure from pressure sensors 6222, 6224, and performs two-chamber FMS procedures and calculations.

An example of a hardware configuration is the combination of a cassette 24 and an APD cycler 14 in which the cassette 24 is installed, as shown in FIG. In this example, the output of cassette 24 is plumbed to a scale, graduated cylinder, or other fluid measurement device.

Referring again to the hardware in FIGS. 53B and 45, a first step 6705 primes the pump or cassette 624 and output line with liquid. Priming also fills the pump chamber 6181 with fluid.

As indicated by the parentheses for cycle 6710, the procedure cycles through steps 6715-6740 multiple times during the air calibration method. The first step of the air calibration cycle 6710 completes the +FMS process 6715, which generates a preliminary measurement of control room volume (VFMSi) when i=1. The air calibration procedure applies equally to other volumetric techniques that may be used alternatively in step 6715. At step 6720, the pressure within control chamber 6171 is approximately increased by controlling first valve 6220 and retaining the gas for a predetermined period of time to allow the gas to come into thermal equilibrium with chamber wall 6172 and gasket 6148. It rises to P1. In one example, the pressure is held at P1 for 15 to 30 seconds. In another example, the pressure increases to P1, pneumatic valve 6220 is closed, and the gas in control chamber 6171 is in thermal equilibrium with walls 6172, 6148. By closing valves 6220 and 6214, control chamber 6171 is isolated. The pressure at the end of step 6720 is recorded in Pli.

At step 6725, hydraulic valve 6190 of cassette 624 is released or opened, allowing pressure within control chamber 6171 to force fluid through hydraulic valve 6190 and onto the scale. In step 6730, the gas or air in the control chamber 6171 reaches pressure equilibrium with the liquid on the pump side 6181 (which occurs quickly) and into thermal equilibrium with the control chamber walls 6172, 6148 (which takes several seconds). Hydraulic valve 6190 is held open long enough so that (possibly). In one example, the hydraulic valve is held open for 15 seconds to 30 seconds. At step 6735, the pressure in the control chamber 6171 is recorded at P2i and the change in the scale is recorded at M _i . The hydraulic valve 6190 is then closed.

In step 6740, a calibration coefficient (CCal) is calculated from the first and second pressures (P1i, P2i) and the displaced liquid mass (M _i ) as follows.

(35)

(35)

where V _CIsoi is the isothermal defined volume of the control room at the i-th position, as follows:

(36)

(36)

where ρ is the density of the liquid in the cassette 624 and V _FMSi is calculated per equations (17), (18), 819) for the +FMS process.

Cycle 5610 can be repeated multiple times until membrane 6148 reaches the opposite side of pump volume or chamber 6181 and contacts spacer 650. In step 6745, an equation for the calibration factor as a function of the FMS defined volume CCal (VVMS) is fit to the data. To obtain a more accurate measurement of the control room 6171 volume for all possible volumes here, we corrected the output of the FMS calculation for the control room 6171 volume described in the previous section as follows: can do.

V _CC = V _FMS・C _cal (V _FMS ) (37)

- Air Calibration for FMS - Also for the FMS process, the calibration coefficients can be obtained by the air calibration procedure described in FIG. - In the FMS air calibration method, the fluid lines to the pump chamber 6181 and the weigh scale (eg, liquid outlet 6191) are primed (step 6705), and the container on the scale is partially filled with liquid. In step 6715, the -FMS process is completed to provide -FMS measurements of control room 6171 volume (VFVMSi) using equations (30), (31), and (32). In step 6720, the pressure in the control chamber 6171 is charged to a pressure P1 that is sufficiently lower than ambient pressure. At step 6725, the low pressure in control chamber 6171 draws fluid into pump chamber 6181 and out of the scale's reservoir. Steps 6730-6745 are the same as described above for the +FMS air calibration procedure. - The resulting formula for the calibration coefficient product CCal (VFMS) as a function of the FMS calculation volume can be applied to the -FMS results.

The accuracy of the V CISOi value can be further improved by considering the improved air calibration values of V _CISOi−1 and V _{CISOi +1} . The procedure described in FIG. 113 sequentially determines the control room 6171 volume, thereby allowing those values to be related. Therefore, the value of V _CISOi can be expected to change smoothly from the i-1th position to the i-th position, to the i+1th position, and so on. This dependence on nearby results is particularly useful at maximum and minimum values, which are more difficult to measure accurately because the volume of liquid moved by the pump is small. The value of any control room volume (VCIsoi) is the previous control room volume ( _VCIsoi-1 ) plus the liquid volume displaced, displaced from the following control room volume ( _VCIsoi+1 ), as follows: can be expressed by two other independent measurements, including minus the liquid volume added.

V _CIsoi =V _CIsoi-1 +ρ・m _i-1 =V _CIsoi =V _CIsoi+1 -ρ・m _i+1
Therefore, the value of V _CIso can be made more accurate by averaging with adjacent values and the displaced volume (ρ·m _i−1 ).

The resulting averaged value V _CIsoi,1 can be averaged again by inserting it into the right-hand side of equation (38), yielding V _CIsoi,2 . This iterative averaging process can continue until the value of V _CIsoi stops changing or converges to a certain value.

This process is slightly different for the first volume and the last volume since there is a value on only one side. The formula for averaging the first volume V _CIso1,1 and the last volume V _CIsoN,1 is as follows.

Again, the resulting average values V _CIso1,1 and V _CIsoN,1 can be inserted on the right side of equations (39) and (40) to calculate V _CIso1,2 and V _CIsoN,2 . This iterative averaging process can continue until the values of V _CIso1 and V _CIsoN stop changing or converge to a certain value. If the initial values of V _CIso1 and V _CIsoN are found to be questionable or unreliable, then the initial values of V _CIso1,2 and V _CIsoN,2 are changed to their more reliable neighbors as follows: Can be set based on

V _CIso1,1 = (V _CIso2 - ρ・m ₂ )
V _CIsoN,1 = (V _CIsoN-1 -ρ・m _N-1 )
Subsequent averaging for V _CIso1,2 and V _CIsoN,2 can then proceed as described above.

Substantially instantaneous or continuous flow and stroke volume estimation In some embodiments, the flow rate into and/or out of the pump chamber of a diaphragm pump is determined while the pumping stroke is occurring. The stroke volume (ie, the extent to which the diaphragm traverses the pump chamber) can be estimated. This can be accomplished during the fluid delivery stroke of the diaphragm pump or during the fluid filling stroke. These estimates may be available during the course of a pump stroke once sufficient data has been collected for controller analysis, allowing the controller to respond to continuously updated pressure information. The cumulative volume of fluid moving in and out of the pump chamber can be calculated. Such real-time information can help determine the end of a stroke early, can reduce the number of partial strokes performed, and can enable more accurate delivery of small volumes or increments of fluid. can deliver precise target fluid volumes more efficiently, can enable early detection of occlusions and other flow reduction conditions, and can aid in priming fluid lines, etc. This information can also be useful in increasing fluid throughput through the pump cassette.

Estimation of flow rate and stroke volume or strobe progression during a pump stroke can be accomplished by monitoring the pressure decay within the control chamber while the pump stroke is progressing. Data generated from monitoring the rate of pressure decay can be used by the controller to determine fluid flow rate through the pump chamber. Pressure decay during a pump stroke indicates the change in control chamber volume as the pump chamber is filled with fluid or emptied, so by monitoring this decay over the course of a pump stroke, the controller can detect the Sometimes the stroke volume can be estimated.

In embodiments where an on/off, binary or "bang-bang" pressure controller is used, the pressure controller repeats the valve to connect and isolate the control chamber from the pressure reservoir to maintain the desired pressure during pumping. It may be necessary to activate it. For example, during a delivery stroke, as fluid is pumped out of the pump chamber, the volume of the associated control chamber increases. This causes the pressure in the control chamber to attenuate. A process or algorithm can be used to apply negative pressure to fill the pump chamber or to apply positive pressure to expel fluid from the pump chamber. As used herein, the term "pressure decay" refers to the decay in the absolute value of the actual pressure being measured (i.e., the decrease toward ambient pressure if a positive pressure is applied, or the ambient pressure if a negative pressure is applied). (increase towards pressure). When the pressure within the control chamber falls outside of an acceptable pressure range, the pressure controller can regulate the control chamber pressure by opening a valve to a pressure reservoir. The allowable pressure range may be within a range of pressure settings. This pressure regulation or maintenance may include connecting the chamber to a suitable pressure source for a sufficient period of time to bring the control chamber pressure back to approximately the desired value and/or within an acceptable range. The pressure again decays as fluid is delivered to and from the pump chamber, and repressurization is again required. This process continues until the end of the stroke is reached.

Repeated repressurization effectively creates a pressure adjustment waveform that appears substantially sawtooth. An example plot showing the pressure adjustment waveform as described above is shown in FIG. As shown, the waveform oscillates between a lower pressure threshold 2312 and an upper pressure threshold 2310. As the stroke progresses, the pressure decays (see data points 2302-2304), fluid exits the pump chamber, and the volume of the control chamber changes. In the example plot of FIG. 42, the control chamber volume is expanding as fluid exits the pump chamber of the diaphragm pump and is pumped to its destination. End of stroke is indicated when the pressure decay levels off 2305, at which point the chamber volume is fixed (i.e., the inlet and outlet fluid valves to the pump chamber are closed) and the pressure of a known reference volume is reached. FMS volume determination can be performed by equalizing 2332 the chamber pressure.

Each pressure decay can be monitored so that the volume of the control chamber can be approximately known during the course of a pump stroke. With this information, the amount of pump stroke volume that has occurred when compared to the initial volume of the chamber can be determined. The initial volume of the pump chamber can be determined, for example, by performing a pre-stroke FMS measurement. The method generally includes determining the volume of a closed chamber by monitoring changes in its pressure when in communication with a reference chamber of known volume and pressure. This determination includes closing the fluid inlet and outlet valves of the pump chamber to ensure a constant volume of the control chamber of the pump, and then connecting the control chamber to the reference chamber. Depending on the heat transfer properties and dynamics of the system, the process can be modeled as isothermal or adiabatic. The system can also be modeled as a polytropic process to optimize measurement accuracy. Other methods of determining the initial volume of the control room can be used. For example, the controller can be programmed to assume that the initial control chamber volume is substantially the control volume physically measured during measurements of the chamber of the pumping system. This assumption may be taken, for example, when the controller calculates that the previous end-of-stroke condition has been fully reached.

The determination of real-time or continuous volume changes in the control chamber and pump chamber of a diaphragm pump during a pump stroke is different from the previously disclosed pressure-based volume determination in which the fluid inlet or outlet inlet remains open and the fluid is substantially different in that it allows for continued flow into or out of the pump chamber. Furthermore, a reference chamber of known volume and pressure is not required. To distinguish this process from a control room/reference room equalization process (a "two-chamber" FMS), the continuous measurement process described herein may be more appropriately considered a "one-chamber" FMS. While the pump chamber remains open to the inlet or outlet fluid lines, the associated control chamber maintains a closed system so that a second volume can be determined once the initial volume is known. Pressure data is repeatedly sampled while the control volume is isolated from the gas source or sink (ie, there is no change in the mass of the control volume). Under these circumstances, controller calculations based on algorithms using polytropic processes can provide more accurate results. This method is now possible because electronic processors capable of rapid data collection and calculations are now available. For example, high-speed application-specific integrated circuits can be employed, or, preferably, FPGA devices can now be dedicated to this task, sharing their computational resources from the main system processor and reducing its efficiency. Reduce the burden of having to do so. In some embodiments, an FPGA is sufficiently robust for the time blocks required to perform on-the-fly or real-time volume measurements during a pump stroke while preserving some resources for other tasks. May be reconfigurable or reprogrammable. Real-time or on-the-fly volumetric measurement can be accomplished by finding the volume of the control room at two points in time, between the closing and opening of the supply valve used to regulate control room pressure or pump room pressure. . The volume difference between the two points in time allows the controller to estimate the flow rate in relatively real time.

As shown in FIG. 42, the high speed controller can collect a series of pressure data points 2302, 2303, 2304, each of which causes the controller to sequentially calculate the chamber volume change associated with each point. can do. Assuming that the controller has determined the starting volume of the control chamber, the change in volume at subsequent pressure decay points can be calculated. The ending volume associated with point 2302 can then be used as the starting volume at 2303, for example to calculate the ending volume at point 2303, and so on.

FIG. 56 shows an example graph 5700 in which traces represent pressure within a control chamber and an estimated pumped volume from that chamber. Volume estimation trace 5702 is generated by sampling pressure data points during each pressure decay 5708 of pressure trace 5704. As discussed above, the controller can use the pressure difference between two pressure data points to determine the volume displaced within the associated pump chamber. The controller can then calculate the cumulative volume of fluid moved into and out of the pump chamber. As further pressure decays 5708 and repressurization events 5706 occur, the cumulative volume indicated by volume estimation trace 5704 increases. Because the processor can rapidly sample and analyze data points, the volume estimate can be continuously updated, as shown in example graph 5700. As a result, the volume delivered to or from the pump chamber can be accurately estimated while the stroke is progressing. This estimate is generated without stopping fluid pumping and without using a reference chamber.

Any suitable mathematical method can be used to model the control (or pumping) chamber pressure decay throughout the pump stroke. However, it is possible that the pressure decay curve at one point in the pump stroke, although appearing very similar to the pressure decay curve at another point in the pump stroke, may represent a different amount of volume change in the pump chamber. should be understood. Programming the controller to analyze the pressure decay curve during a pump stroke by using a polytropic model can help resolve these possible differences in volume change.

A one-chamber FMS (which uses a polytropic model to calculate real-time or continuous volume changes in a control or pump chamber) uses a binary orifice valve or variable It may be possible to implement it in a system using any orifice valve. During the time that either type of valve is closed (although this period may be much shorter than if a variable valve is used), pressure data can be collected and analyzed. In either case, the pressure decay while the fluid is exiting (or the pressure rise while the fluid is entering) can be sampled, the volume change can be calculated, and the process can be repeated to calculate the real-time volume Change data can be provided. In the following description, a polytropic modeling process is applied to a system that uses binary valves to regulate pressure in a control room or pump chamber. This description applies to other types of valves and pressure regulation protocols.

In general, the one-chamber FMS protocol can be applied to any gas-powered (eg, air-powered) diaphragm pump where the fluid pump chamber is separated from the control chamber by a flexible diaphragm. During a pump stroke, as fluid enters or exits the pump chamber, the controller regulates the pressure delivered to the control chamber and the diaphragm, so that the control chamber is, at least part of the time, a closed system. Become. When the pressure within the control chamber reaches or exceeds a high threshold, a valve connecting the control chamber to the pressure source closes. As the pressure decays from fluid movement in and out of the pump chamber, the valve opens again (fully or partially) and the control chamber is closed to incoming or outgoing air during the pump stroke. Alternating periods are provided. During these stages when the control room is isolated, changes in pressure reflect changes in the volume of the control room and therefore of the pump room. The initial volume at the beginning of the pressure decay period must be known or estimated from previous measurements. The ending volume can then be calculated from the measured pressure difference between the initial volume and the ending volume. The ending volume can then be used as the initial volume for the next calculation, as the pressure further decays during the control room isolation phase. In this way, the controller can quickly collect pressure measurements during the pressure decay phase of the pump stroke to calculate almost continuously the change in volume of the pump chamber, and therefore The instantaneous fluid flow rate leaving the can be estimated. The relationship between pressure and volume of a gas in a closed system is controlled by standard equations describing the behavior of an ideal gas, and it may be optimal to assume a polytropic process in the calculations, where the polytropic coefficient can vary between 1 and a value representing the specific heat ratio of the gas used in the pump (the adiabatic coefficient for that gas).

The polytropic coefficient is controlled by the following equation:
PV ⁿ = constant where P is pressure, V is volume, and the polytropic exponent “n” is 1 and γ (γ is 1.4, and is an adiabatic system for most gases including air. ) is the number between . Since the right side of the equation is a constant, two consecutive points in time can be compared. To compare two consecutive time points, the following formula can be adopted.

where P _t is the pressure at time t, V _t is the volume at time t, P _t-1 is the pressure at time t-1, and V _t-1 is the volume at time t-1. . Rearranging and simplifying the equations to solve for V _t yields the following equation:

As shown in the above equation, the current volume of the chamber, _Vt , can be determined if the volume at the end of the previous time interval is determined. This volume can then be used to determine the stroke volume if desired. Additionally, by tracking the length of time between V _t and V _t-1 , it is possible to determine the flow rate over that period. By averaging multiple flow rate determinations using successively paired pressure data values, an average flow rate over a portion of the pump stroke can be determined. Additionally, knowing the starting and nominal ending volumes of the control chamber allows the length of time required to complete a pump stroke to be determined independently. In an example, the data sample set may be collected every 10 milliseconds and may include 20 data samples. In such an embodiment, the length of time between V _t and V _t-1 would be 0.5 milliseconds. The preferred data sampling rate depends, among other things, on the expected duration of the pump stroke, the rate of pressure decay observed by the controller, the degree of measurement error or noise associated with the pressure signal, and the sampling rate and processing capacity of the controller (e.g., Depends on whether a dedicated FPGA is used or not.

In some embodiments, the controller can calculate volumetric data at each sampled data point. This has the advantage of minimizing the effects of heat transfer between the measurement points. On the other hand, signal noise during measurements can result in less accurate calculations for actual volume changes. In another embodiment, the processor may sample the set of pressure data points within a period during which heat transfer is estimated to be at an acceptable level, and the pressure data set may be filtered or smoothed by the processor. and then, at the end of that period, the final volume is calculated using the initial smoothed pressure measurement and the final smoothed pressure measurement. Therefore, the influence of signal noise on measurement accuracy can be reduced.

There are periods during the pumping stroke where pressure data collection is not possible or advisable. For example, when the pressure supply is open and the pump chamber pressure is rapidly increasing, fluid continues to flow into or out of the pump chamber. As a first approximation, it can be assumed that the fluid flow rate during this short period remains approximately unchanged from the flow rate measured just before the opening of the pressure supply valve. The volume change thus estimated can then be added to the volume representing the last measured pressure data point to arrive at the initial volume for the next measured pressure data point. Additionally, there may be defined points during a stroke where pressure data points may be ignored. For example, depending on the data sampling rate, pressure information just before a pressure increase during a pressurization event may be inaccurate. There may also be some aliasing for data points immediately following a pressurization event. In embodiments, data points collected by the controller within a predetermined period of time before and after a pressurization event may be discarded or ignored to further improve the accuracy of the flow determination process.

In embodiments that use FPGAs for pressure data collection and analysis, problems resulting from lower sampling rates may be less significant. In some embodiments, the FPGA may also have resource capacity to control associated valves in the pumping system. By controlling the pressure supply valve, the FPGA may be able to schedule sampling of pressure data more efficiently. Event synchronization can be improved and aliasing problems due to data sampling can be reduced.

Some estimations can also be made at the beginning of the pump stroke. There may be a small amount of fluid movement into or out of the pump chamber before the first pressure decay event. Although inertial forces may limit the initial fluid flow, the controller can be programmed to estimate the initial fluid flow and volume change before the first data sampling point during pressure decay. Such estimation can allow estimation of changes in chamber volume while pressure decay information is not available at the beginning of the stroke. The amount of fluid estimated to have been moved at the beginning of the stroke may depend on the pumping pressure applied to the control chamber and pump chamber. The controller can be programmed to include a predetermined volume of fluid movement based on the value of applied pressure. Alternatively, multiple data points can be sampled to determine the estimated flow rate, and then the flow rate can be used to extrapolate to the volume moved while no data were available. . For example, it may be assumed that the flow rate over that period was substantially equal to the current estimated flow rate. This assumption that the flow rate is constant can then be used to determine an estimate of the volume moved over the period for which no data was available.

FIG. 57 shows a flowchart detailing example steps that can be used to estimate control chamber volume changes during a pump stroke. As shown, the flowchart begins at step 5200 where certain pre-stroke FMS measurements are taken, which in embodiments include fixing the volumes of the pump chamber and control chamber and measuring the control chamber pressure. , including a reference volume chamber and pressure equalization. This measurement can provide a starting control room volume measurement. Alternatively, if the controller calculates that the previous end of stroke of the pump chamber is completely completed, the starting control chamber volume can be assumed by the controller to be a constant and known amount. Then, in step 5202, a pump stroke can begin. At step 5204, control chamber pressure decay (or decay in absolute value of pressure) can be monitored as the stroke displaces fluid and moves fluid into or out of the pump chamber. In some specific embodiments, multiple data points can be sampled along each decay curve and the mathematical model described above can be used to determine the change in control chamber volume as the pump stroke progresses. Can be done. Data points and volume information can be stored in memory 5208.

Assuming no end of stroke is detected, step 5210 may be performed when the pressure within the control chamber falls outside a predetermined range (eg, below a predetermined pressure value). In step 5210, the pressure controller performs pressure maintenance on the control chamber (i.e., repressurizes the control chamber) to bring the control chamber pressure approximately (e.g., may be at or near the higher pressure limit of the range) to a predetermined desired level. Can be returned to value. After completing step 5210, step 5204 may be repeated while the collected data is again stored in memory 5208. This can continue until an end-of-stroke condition is detected. Detection of the end of a stroke is described elsewhere.

If an end-of-stroke condition is detected, a post-stroke FMS measurement (determining volume by measuring control gas pressure) may be performed in step 5212. This measurement can be compared to the measurement from step 5200 to confirm and/or more accurately determine the total volume moved during the stroke. Additionally, this post-stroke FMS measurement can serve as the starting control chamber volume measurement for the next stroke performed by that pump chamber.

Other means of determining when the pump has completely completed its pump stroke may be used. If so, the results of that determination can then be used to initialize the controller to the starting volume of the control chamber for the next pump stroke. Methods other than volume determination by pressure measurement can be used to evaluate the final volume of the control chamber and pump chamber, whether or not the pump stroke is completely completed. However, the final chamber volume can be determined and then used to initialize the controller to the starting volume of the chamber for the next pump stroke.

The polytropic coefficient "n" of the mathematical model described above can be initialized with a predetermined value. For example, in some embodiments, the factor may be set to 1.4 or γ (representing an adiabatic process with respect to air). Initialization values may vary depending on the embodiment, type of control fluid, or intended flow rate. For example, relatively fast flow embodiments may be better modeled as an adiabatic system, and slower flow embodiments may be better modeled as an isothermal system.

The coefficient can then be adjusted over multiple pump strokes to a value that provides a greater match between the calculated real-time flow rate and the measured final volume change at the end of the stroke. This can be done by using feedback collected over one or more pump strokes using any suitable software algorithm, or by using a controller such as a proportional or PID controller. Feedback may be in the form of a calculated delivered volume determined by a comparison of pre-stroke and post-stroke FMS measurements. The final FMS measured volume can be compared to the estimated real-time volume change determined using the current value for "n." If their volumes differ by more than a predetermined amount, the value for "n" can be adjusted. The new coefficient value can then be saved and used as the initial value for the next pump stroke. In the example, data collected over several pump strokes can be used to adjust the factor "n." For example, the values of "n" that resulted in the final (eg, FMS measured) volume moved for multiple strokes can be averaged together. In the absence of significant changes in ambient conditions (e.g., changes in fluid or environment temperature), averaging or other numerical filtering procedures can reduce the time required to produce accurate flow and stroke volume measurements. This is possible because it may not be necessary to have the controller repeatedly compare pre-stroke and post-stroke FMS measurements.

FIG. 58 shows a flowchart outlining an example of steps for adjusting the coefficients of a mathematical model as described above. As shown, in step 5220, pre-stroke FMS measurements may be taken to determine a starting volume for the control chamber. Then, in step 5222, a stroke can begin. At step 5224, pressure decay in the pressure regulation waveform can be monitored. Using an example mathematical pressure-volume model with predefined initial exponential coefficient values, the volume change in the control room can be determined. Once the stroke is complete, a post-stroke FMS measurement may be performed to determine the end-of-stroke control chamber volume in step 5226. At step 5228, the volume measurements from steps 5220 and 5226 may be compared to determine the total control chamber volume change versus stroke. Based on this comparison, the coefficients can be adjusted to align the two final values if necessary. For example, the coefficient can be adjusted to the value that resulted in the volume change found by using FMS measurements.

As mentioned above, flow estimates as the stroke is progressing include, but are not limited to, detecting occlusions, detecting low or no flow conditions, detecting end of stroke, detecting fluid line priming conditions, etc. Can be used for multiple purposes. The flow rate estimate can be monitored to determine whether an end-of-stroke condition may exist. For example, if the real-time flow rate drops below a predefined threshold (e.g., 15 mL/min), a pump stroke is fully completed (i.e., the maximum volume of fluid has been moved, considering the physical limitations of the pump). may indicate that If the flow rate estimate drops below a predefined threshold, FMS measurements can be performed on the chamber to confirm the volume delivered. If the FMS measurement determines that the end of the stroke has been reached, the chamber can move on to the next pumping operation (or pump stroke). If the end-of-stroke condition has not been reached, the controller may take a number of actions, including, for example, attempting to restart the pump stroke. Alternatively, detection of a reduced flow condition may indicate a fluid line occlusion and may trigger an occlusion warning or alarm, or attempt fluid pushback to determine if an occlusion exists. be able to.

In some embodiments, the controller may be programmed to have an arming routine (software trigger) to prevent the controller from prematurely declaring an end-of-gas stroke condition. This can help avoid false triggering of end-of-stroke determination. For example, the lack of accumulated pressure data at the beginning of a stroke can increase the impact of signal noise on flow determination. In an example, the controller may be programmed such that the trigger is only actuated after a predetermined period of time after the initiation of a pump stroke. In some embodiments, the software trigger may be the achievement of a predetermined flow rate value. Alternatively, the trigger may be actuated after the controller estimates that a predetermined volume of fluid has been moved. Requiring the end-of-stroke detection trigger to be actuated before an end-of-stroke condition is detected can help reduce the number of partial strokes performed, increasing the throughput of fluid through the pump cassette. can help you. The trigger may be enabled after the stroke has progressed for a predetermined amount of time to help prevent a scenario in which the enable criterion is not reached and the end of the stroke is never detected. In other embodiments, the end of the stroke may be automatically triggered after a predetermined period of time has elapsed since the beginning of the stroke without an enablement criterion being met.

FIG. 59 shows a flowchart outlining several example steps for detecting end of stroke based on real-time flow estimates. As shown, in step 5240, a starting volume of the control chamber can be determined by taking a pre-stroke measurement. Then, in step 5242, the pump stroke begins. As the stroke progresses, the pressure decay in the control chamber pressure regulation or maintenance waveform is monitored in step 5244. Based on the pressure decay, the flow rate is estimated. Once the end-of-stroke enablement criterion is met, the controller determines whether the flow rate exceeds a pre-established or predetermined flow rate. If the flow rate exceeds the predetermined flow rate, pump stroke continues in step 5246 and flow estimation continues in step 5244. If the flow rate drops below the predetermined flow rate, then in step 5248 the stroke may have reached the end and an end-of-stroke FMS measurement can be taken to determine the control chamber volume.

In some embodiments, an estimate of control chamber volume change over the course of a stroke can be used to predict the length of time required to complete a stroke. Since the nominal or predicted end-of-stroke volume is known and the control chamber volume change can be used to determine the flow rate, the controller uses this information to estimate how long the entire stroke should take. can do. Correspondingly, the controller can calculate an estimate of how much time is required to complete the remaining portion of the stroke. Once the predicted end-of-stroke time is reached, the stroke can be stopped and FMS measurements can be taken. If the FMS measurement indicates that the gas stroke is a partial stroke, multiple actions can be taken. In some embodiments, the cycler may attempt to retry the stroke. Alternatively, detection by the controller of a reduced flow condition may be indicative of an occlusion warning or alert, or to determine whether a pushback attempt can be made to alleviate an end-of-line occlusion. I can do it.

FIG. 60 depicts a flowchart outlining several example steps that may be used to determine the end of a stroke by predicting the time required to complete the stroke. As shown, in step 5250, a pre-stroke FMS measurement may be taken to determine the starting volume of the control chamber. A stroke is initiated in step 5252. Once the stroke begins, a stroke timer may be started in step 5254. As the stroke progresses, the pressure decay in the pressure regulation or maintenance waveform for the control chamber is monitored in step 5256. This can be used to estimate the control chamber volume and flow rate. These estimates can then be used to predict the estimated stroke time in step 5258. By finding the difference between the current chamber volume and the predicted end-of-stroke chamber volume, the estimated stroke time can be calculated. The estimated flow rate can then be used to find the length of time required to complete the stroke. If the estimated stroke end time is longer than the elapsed stroke time, steps 5256, 5258, and 5260 may be repeated. If the estimated end-of-stroke time is less than or equal to the actual elapsed stroke time, the controller may declare an end-of-stroke condition. In step 5262, the stroke ends and FMS measurements can be taken to determine the post-stroke volume of the control chamber. In some embodiments, remaining stroke time estimation may be performed until a predetermined length of stroke time remains or a predetermined amount of stroke volume has occurred. The controller continues stroking until the time has elapsed, after which step 5262 can occur.

The availability of real-time flow estimates provided by the exemplary mathematical models described above may similarly enable early detection of reduced flow conditions. Program the controller to respond to a real-time flow rate that is less than a predicted flow threshold, instead of having the controller wait for the end of the stroke, take a volume measurement, and compare that measurement to a previous measurement. be able to. The controller can be programmed to stop the pump stroke at that point and take more precise volume measurements (eg, via FMS measurements) to confirm the flow rate estimate. Thus, a reduced flow condition can be detected without the need to complete the extended pumping stroke caused by the reduced flow. This can save time, reduce patient discomfort, and help increase the overall fluid throughput of the pump cassette. It is also possible to allow the treatment to move quickly from the end of the draining phase to the filling phase of the next cycle. This increased efficiency allows for longer treatment times to be allocated for residence. In one example, the controller can be programmed to declare a reduced flow condition when the flow rate estimate is less than a 50 mL/min threshold. In some embodiments, the flow rate may have to remain below a threshold for a predetermined period of time (eg, 30 seconds) before a reduced flow condition is declared.

Optionally, there may be multiple flow reduction state classification schemes defined by different flow thresholds. For example, the controller can be programmed to recognize a "no flow" threshold that is set lower than the low flow threshold (e.g., <15 mL/min) in addition to a low flow threshold (e.g., <50 mL/min). can.

FIG. 61 shows a flowchart outlining several example steps that can be used to detect a reduced flow condition during a pump stroke. As shown, in step 5270, a pre-stroke FMS measurement may be taken to determine the starting volume of the control chamber. The stroke is then initiated in step 5272. At step 5274, the pressure decay in the pressure regulation or maintenance waveform can be monitored, thereby estimating real-time control chamber volume changes and flow rates. As long as the flow rate exceeds the predetermined flow rate for the predetermined period of time, the controller continues the pump stroke. The controller continues to monitor the pressure decay waveform as described in step 5274. If the end of stroke is reached, an end of stroke FMS measurement may be performed in step 5276 to determine the end of stroke control chamber volume. If the controller determines that the flow rate is less than a predetermined flow rate for a predetermined period of time, an FMS measurement may be taken at step 5278 to confirm that a reduced flow condition exists. If a reduced flow condition is not confirmed, the stroke can continue and the controller continues to calculate flow based on the control chamber pressure adjustment or maintenance waveform as described above in step 5274.

If a reduced flow condition is confirmed by the FMS measurements at step 5278, a reduced flow or occlusion notification, warning, or alarm may be sent to the user at step 5280. This can be done via the user interface and can be accomplished by audible messages or voices, vibrating displays, etc. The response generated by the cycler controller may depend on the sensed flow rate. Pushing fluid back into the fluid reservoir (or into the peritoneal cavity, depending on the fluid line) can be triggered prior to indicating that an occlusion exists. If the pushback attempt is unsuccessful, the controller may issue an occlusion warning.

In some embodiments, if a reduced flow condition is detected, the cycler controller determines whether a target volume for the pumping operation (e.g., drainage phase) has been achieved (e.g., completion of peritoneal drainage). be able to. If more than the target volume has been moved, the controller may declare the pumping operation complete. In some embodiments, the device controller allows a minimum defined amount of time to elapse to ensure that the fluid reservoir (e.g., solution bag, heater bag, or patient's peritoneum) is substantially empty. You can request that you do so.

Real-time measurement of fluid flow during a pump stroke allows targeting a predetermined fluid volume delivery less than, or an integer multiple of, a full pump stroke volume. The controller can be programmed to end the stroke when the chamber volume change estimated through pressure measurements indicates that the target volume has been delivered or withdrawn. When this occurs, the controller can initiate FMS measurements to confirm that the target volume has indeed been reached. Real-time fluid flow measurements can eliminate the need for multiple FMS measurements while allowing repeated small volume partial strokes to avoid exceeding the target volume. Such a targeting scheme may be particularly desirable in pediatric applications where the amount of time spent approaching but not exceeding the target volume is inherently relatively long in the pumping operation.

FIG. 62 shows a flowchart outlining several example steps that can be used to determine when a target volume of fluid has been moved. As shown, the step utilizes an estimated displaced volume based on measurements of pressure decay during the stroke to end the stroke when the target volume is estimated to have been achieved. At step 5290, the pumping operation begins. This operation may be, for example, a filling phase for a peritoneal dialysis cycle. Once the pumping operation is initiated, FMS measurements can be taken and the pump stroke is initiated, as shown in step 5292. During the stroke, pressure decay in the pressure regulation or maintenance waveform can be monitored at step 5294. This allows estimation of volume and flow rate as the stroke progresses. At step 5296, the stroke can end and post-stroke FMS measurements can be taken. The cycler controller tracks the calculated solution volume to ascertain whether the difference between the target volume and the total volume of fluid delivered during the pumping operation is greater than the total pump chamber volume. If so, the controller continues to command the next pump stroke in step 5297. Steps 5294, 5296, and 5297 can be repeated until the difference between the target volume and the total volume pumped is less than the volume of one total pump chamber. If the target volume is exceeded by delivery of another full chamber volume at step 5298, then step 5298 is performed.

At step 5298, a target setting trigger can be set as the difference between the total delivered volume for the pumping operation and the target volume for the pumping operation. The pump stroke can then continue at step 5300 until the controller calculates through pressure decay measurements that the target volume has been reached. A calculated point in time, step 5302, can be taken where the stroke is completed and an FMS measurement can be taken to confirm that the target volume of fluid has been moved.

By calculating the estimated flow rate from the pressure decay curve during the pump stroke, the controller can also pre-close one or more valves to more precisely deliver a predetermined fluid volume. That is, a delay between the controller command and the mechanical response of the valve may be allowed to close the valve before the target volume is delivered. The flow generated during the period required to physically close the valve can then substantially fill the target volume. In particular, the controller can estimate the amount of time required to physically close the valve. In some embodiments, this estimate may be a preprogrammed value. For example, for a particular valve configuration, the response delay can be approximately 100 milliseconds. Based on the real-time calculation of flow rate, the volume of fluid displaced during the valve response delay can be estimated. This amount of fluid can be subtracted from the target volume to provide the valve closure trigger volume. Once the valve closure trigger volume is filled, the cycler controller can command the valve to close.

Volumetric Pumping Volumetric Calibration Volumetric pump measurements made by cycler 14 can be calibrated before cycler 14 is provided to a patient. As an output of calibration, cycler 14 may be provided with calibration data that is then used during pumping to adjust the volume measurements collected by cycler 14. This may help reduce errors in volume calculations specific to a particular cycler 14. As discussed elsewhere herein (see, e.g., FIGS. 53A-55), calibration involves attaching the disposable cassette 24 to the cycler 14 and pumping fluid to or from the mass scale. This can be achieved by A calibration factor for cycler 14 may be calculated based on the transmitted measured mass and the FMS value calculated by cycler 14.

However, such calibration may be subject to some variation in its accuracy depending on manufacturing differences between disposable cassettes 24. Such differences may occur between manufacturing lots of cassettes 24. Additionally, differences may exist within a particular lot. The aspect of the sheet or membrane 15 on the cassette 24 can potentially contribute to some degree of variability. If preformed regions are included in sheet 15, some variability may be due to the preformed production process. Additionally, during the calibration process, cassette 24 may be in a liquid-containing or wet state. If air remains in the cassette 24, this air can affect the calibration.

In some embodiments, one or more volumetric standard sets or volumetric calibration cassettes can be used in place of disposable pump cassette 24 during calibration. Although described in connection with the cycler 14 detailed herein, such volumetric standard cassettes may be used in other cassette-based pump systems as well. Generally, the volumetric cassette is of similar dimensions and has the same general layout as the disposable cassette 24 so as to interface with the cycler 14 and seal against the control gasket 148 as if it were a disposable cassette 24. It is possible. In the case of a volumetric standard cassette serving as a disposable cassette analog, calibration can be performed under similar conditions as exist in a typical disposable cassette 24. The cycler 14 can apply pressure to the volumetric standard cassette through the control gasket 148 in the same manner as the disposable cassette 24. Volumetric standard cassettes may not pump fluid or may not be used for fluid pumping at all, but can be used to make volumetric measurements based on the gas law, as described above. Since the pump chamber area of various volumetric standard cassettes can be designed to mimic a particular pump chamber fill volume, the cycler 14 knows what the result of its measurement should be and uses the control chamber 171B (e.g. , see Figure 43). Therefore, by performing a volumetric measurement of the control room 171B (see, e.g., FIG. 43) using a volumetric calibration cassette, a calibration can be performed to adjust for errors in the volumetric data collected by that particular cycler 14. I can do it. Cycler specific and not subject to single-use cassette variations, limitations associated with mass scale resolution, or other factors. Additionally or alternatively, such volumetric calibration cassettes may be used as part of a process testing procedure during manufacturing. For example, a volumetric cassette can be used to establish an ideal baseline for cycler 14. Disposable cassette 24 may be tested by cycler 14 and compared to this baseline. If a disposable cassette 24 deviates from the ideal baseline by more than a predetermined amount, a related disposable cassette 24 (eg, from the same lot) can be singled out for further testing.

These volumetric standard cassettes can be constructed of sturdy, rigid, and dimensionally stable materials. For example, various metals can be used, such as steel or aluminum. In certain embodiments, plastics such as ABS, polycarbonate, acrylic, Artem, Peak, and/or PET can be used. Other materials such as ceramic, glass, etc. are also possible. These volumetric calibration cassettes can be constructed by machining, injection molding, material addition processes (such as 3D printing), or made in any other suitable manner. The volumetric calibration cassette may emulate a pre-prepared cassette with flow channels filled with fluid. The pump chamber areas of these cassettes can be designed to have a predefined shape selected to represent the desired fill volume in an ideal disposable pump cassette 24. Several volume measurement standard sets reflect a variety of selected fill volumes (e.g., substantially full, substantially empty or completely delivered, and any number of fill volumes in between). It can be constructed as follows. The shape of the pump chamber on a volumetric calibration cassette of any particular volume can be selected to have a shape similar to that present in disposable cassette 24 if its pump chamber 181 contained the same volume. In some embodiments, the shape of the pump chamber on the volumetric standard or calibration cassette mimics the shape of the pump chamber 181 of an ideal disposable cassette 24 when manipulated by the cycler 14 to contain the desired volume. It is possible. The surface areas of the pump chamber regions of any volumetric standard set may all be substantially equal, even if the volumetric standard sets are configured to represent different volumes. This may be desirable since the seat 15 of the disposable pump cassette 24 exhibits minimal elongation over the range of the pumping stroke. Therefore, the surface area of the pump chamber region 151 of the seat 15 should not substantially change regardless of the volume contained in the pump chamber 181 of the disposable pump cassette 24. Method during volume measurement of installed volumetric calibration cassette. After construction, the capacity of the capacity calibration cassette can be verified. This can be done by weight, water displacement, characterization performed on a vision system, measurements on a 3D CMS, or any other suitable method. In some examples, the surface area of the pump chamber region of the volumetric calibration cassette can also be verified.

63A-63C, several views of an exemplary disposable cassette 24 are shown. figure. A top view of the disposable cassette 24 is shown. Disposable cassette 24 is shown in FIG. 63 and in cross-section in FIGS. 63B and 63C (taken at the corresponding cut plane in FIG. 63A). As shown in FIG. 63B, disposable cassette 24 includes a number of channels passing through central body 44 of cassette 24. As shown in FIG. Additionally, there are several walls 46 and valve ports 186 that project away from the central body 44 of the cassette. A rim 48 exists around the disposable pump cassette 24 and extends to a height greater than the height of the wall 46. The membrane 15 is attached to this rim 48. These features are explained in more detail above.

Referring to FIG. 63C, pump chamber 181 of disposable pump cassette 24 is shown in a delivered condition. In this state, the membrane 15 is opposed to the spacer 50 which leaves some volume of the pump chamber 181 to act as an air trap during operation. Pump chamber 181 and spacer 50 are further described above. The disposable cassette 24 shown includes several inlet/outlet ports 150, 152, 154, 155.

In contrast, FIGS. 64A-64C show various views of an exemplary volumetric or standard calibration cassette 4000A. This volumetric cassette 4000A and others described herein are similar to those shown in FIGS. 63A-63C and elsewhere herein (e.g., the spikes shown in FIG. 6). 160 may be used to calibrate the cycler 14 to operate with a disposable cassette 24 similar to the disposable cassette 24 with a cassette 160. A top view of an exemplary volumetric calibration cassette 4000A is shown in FIG. 64A. Volumetric calibration cassette 4000A may have an overall footprint comparable or nearly identical to disposable cassette 24. A volumetric calibration cassette, such as volumetric calibration cassette 4000A, cannot include sheet 15. In FIG. 64B (cross section taken at line 64B-64B in FIG. 64A), volumetric calibration cassette 4000A may lack flow passages, orifices, valve ports, pass-throughs within midbody 4044, etc. Calibration cassette 4000A may include a solid midbody 4044. Midbody 4044 may be thicker than that of disposable cassette 24. For example, the midbody 4044 can be at least twice as thick, or 2 to 3 times as thick as the midbody 44 of the disposable cassette 24 (see, eg, FIG. 63B). The exemplary midbody 4044 extends over a majority (about 2/3) of the thickness of the volumetric calibration cassette 4000A. The thickness of the central body 4044 can be between 1/2 and 3/4 of the thickness of the thickest portion of the volumetric calibration cassette 4000A in various embodiments.

The exemplary volumetric cassette 4000A (and others described herein) includes a wall 4046 in the same location as the disposable cassette 24. These walls can extend from midbody 4044 to the same point as disposable cassette 24. In some embodiments, the side of the volumetric standard cassette opposite the pump chamber may be wallless and substantially flat. The wall can act as a sealing wall or rib that presses against a portion of the control gasket 148 when the volumetric calibration cassette 4000A is installed in the cycler 14. Thus, the wall can ensure that the control room 171 of the cycler 14 is isolated from communication with other areas of the control gasket 148 after the volumetric cassette 4000A is installed within the cycler 14. .

The exemplary volumetric calibration cassette 4000A also includes a protrusion 4048. These projections 4048 are located at the location of the valve port 186 of the disposable cassette 24 and extend to the same height as the valve port 186 of the disposable cassette 24 . Protrusion 4048 is solid. Orifice not included. In alternative embodiments, an orifice may be included. Each protrusion may be completely surrounded by a wall extending from the central body 4044.

In the example, the walls and protrusions 4048 are shorter in height as measured from the surface of the centerbody 4044 due to the enlarged centerbody 4044. In some embodiments, the walls and/or protrusions 4048 can extend to a point slightly above their respective ends. A point at the wall or valve port 186 within the disposable cassette 24. For example, the walls and/or protrusions may extend an additional distance equal to (or approximately the same, but perhaps slightly greater) the thickness of the membrane 15. This may help make the volumetric calibration cassette 4000A more closely analogous to the disposable cassette 24 when attached to the cycler 14 for a calibration procedure. The wall may have a height sufficient to prevent gasket 148 (see, e.g., FIGS. 33A-C) from contacting midbody 4044 when volumetric calibration cassette 4000A is attached to cycler 14. .

Additionally, the draft present on the disposable cassette 24 to facilitate molding may be removed within the volume calibration cassette 4000A, particularly if the volume calibration cassette 4000A is machined. Similarly, certain curvatures, such as the radius of the walls or edges of volumetric calibration cassette 4000A, can be removed or made tighter to facilitate machining. In some embodiments, protrusion 4048 may be omitted as well. Because the exemplary volumetric calibration cassette 4000A does not include a seat 15 (ie, is open-sided), the rim 48 present on the disposable cassette 24 may be at a uniform height with the walls 4046 of the calibration cassette 4000A. Additionally, the inlet/outlet ports 150, 152, 154, 155 can be removed. In FIG. 64C, instead of spacer 50 (see, eg, FIG. 63C), pump chamber region 4181A of volumetric calibration cassette 4000A can be solid. Other volumetric calibration cassettes described herein may be of similar construction. Although the volumetric calibration cassettes shown herein are depicted as solid, certain embodiments may be hollow or have hollow regions.

Several exemplary volumetric calibration cassettes 4000A-D are shown in FIGS. 64D-67B. The volumetric calibration cassette 4000A shown at 64A-64D is constructed such that its pump chamber area 4181A is shaped to mimic a fully delivered condition in an ideal disposable cassette. 65A-65B illustrate another volumetric calibration cassette 4000B whose pump chamber region 4181B is configured to mimic a partially filled disposable cassette 24 pump chamber 181. 65A-65B each have a shape representing a 5.625 ml fill volume within an ideal disposable cassette 24. Another volumetric calibration cassette 4000C is shown in FIGS. 66A-66B. This volumetric cassette 4000C is reshaped so that its pump chamber region 4181C mimics a partially filled disposable cassette 24 pump chamber 181. Figures 66A-66B have a geometry that represents an ideal disposable cassette 24 fill volume of 11.250 ml. 67A-67B show an example of a further volume calibration cassette 4000D with a pump chamber region 4181D that mimics a partially filled disposable cassette 24 pump chamber 181. Each pump chamber region 4181D has a shape that represents a fill volume of 16.875 ml in an ideal disposable cassette 24.

Cross-sectional views of volumetric calibration cassettes 4000B-D (all taken at section plane 64C-64C of FIG. 64A) are shown in FIGS. 68A-68C. As shown, the pump chamber regions 4181B-D of the volumetric cassettes 4000B-D may be contoured to mimic the curvature of the membrane 15 within the disposable cassette 24 as the pump stroke occurs. This may help ensure that control gasket 148 can sit flush against volumetric calibration cassettes 4000B-D when volumetric measurements of control chamber 171 are being made. In other embodiments, the contours of pump chamber regions 4181B-D may be constructed with sharper features. That is, the curvature may be smaller in radius and the pump chamber regions 4181A-D may have portions that are plateaus, flat, or nearly flat. Preferably, volumetric calibration cassettes 4000B-D should be constructed such that their pump chamber regions 4181B-D do not have any undercut features. However, some volumetric calibration cassettes may have a portion in their pump chamber region that is perpendicular to the midbody 4044 or approximately perpendicular to the midbody 4044.

Several exemplary volumetric calibration cassettes 4000E-H are shown in FIGS. 69A-69B. These volumetric calibration cassettes 4000E-H include pump chamber control regions 4181E-H with sharper features and some plateau regions. 69A-69B illustrate a volume calibration cassette 4000E structured such that its pump chamber regions 4181E each have a shape representing a fill volume of 5.625 mL. The volumetric calibration cassette 4000F shown in FIGS. 70A-70B is configured such that each of its pump chamber regions 4181F has a shape representing a fill volume of 11.250 mL. 71A-71B illustrate a further example volume calibration cassette 4000G in which the shape of the pump chamber region 4181G represents a fill volume of 16.875 mL. The exemplary volume calibration cassette 4000H of FIGS. 72A-72B has pump chamber regions 4181H each shaped to represent a complete pump chamber volume (22.5 ml) within the disposable cassette 24. Cross-sectional views of volumetric cassettes 4000B-D (all taken at cut planes 64C-64C of FIG. 64A) are shown in FIGS. 73A-73D.

The fidelity of pump chamber regions 4181A-H to the actual shape of sheet 15 assumed by disposable set 24 when filled with a predetermined volume may be more important depending on the type of volumetric measurement performed. There is. If you can do positive and negative FMS (above), something more faithful may be desirable. In certain instances, the shape of the sheet 15 is configured to pump an epoxy or the like (e.g., a filler-containing epoxy) through a disposable cassette and allow the epoxy to cure when the pump chamber of the disposable cassette is in the desired filling or delivery state. can be determined or approximated by Preferably, the epoxy or other material used can exhibit predictable or minimal volumetric shrinkage during curing.

Referring to FIG. 74, a flowchart 4100 is shown detailing some example actions that may be performed to perform a calibration with at least one volumetric calibration cassette. As shown, a volume standard or calibration cassette may be installed in the cycler 14 at block 4102. This includes locking the door 141 and inflating an air bladder at the door 141 (see, e.g., FIG. 31) behind the mounting location 145 and the mounting location 145 and the control surface 148 (e.g., see FIG. 31). , see Figure 31). The volumetric standard cassette can be placed in the same mounting location 145 as the disposable pump cassette 24 used in administering the treatment. Accordingly, attachment location 145 may be configured to receive both a disposable pump cassette 24 and a volume calibration cassette. The fluid trap may also be exposed to negative pressure at block 4102. Cycler 14 may measure the volume of the pump chamber region of the volumetric standard cassette installed at block 4104. Volume measurement of the pump chamber area of the volumetric standard cassette. For example, it may be indirect via volumetric measurement of the control room. To do this, cycler 14 may perform FMS measurements as described above. At block 4106, cycler 14 may return to block 4104 if there are additional measurements to be made using the volumetric calibration cassette. Typically, cycler 14 can perform several FMS measurements for each control room 171. After completing or completing a portion of the fill stroke, perform some FMS measurements, as if performing volumetric measurements (eg, FMS measurements as described elsewhere herein). Cycler 14 may perform several FMS measurements, such as performing FMS measurements after completing or completing a portion of a delivery stroke. Additionally, cycler 14 may perform some measurements using positive FMS and some measurements using negative FMS. These processes are described in detail above. Any measurements taken may be taken individually from each of the control rooms 171 of the cycler 14. Additionally, measurements may be made for different fill and delivery pump pressure pairs utilized by cycler 14. For example, cycler 14 may use a relatively low pressure and then a high delivery pressure to improve patient comfort when pumping fluid from the patient to a destination. When pumping from a source solution bag to a heater bag, high fill and supply pressures can be used to speed up fluid movement. Such pump pressure pairs are described in more detail elsewhere herein.

Once all measurements have been made for a particular volume standard or calibration cassette, other volume calibration cassettes can be installed to more accurately create a correction curve. If there are additional volumetric cassettes at block 4108, the door of the cycler 14 may be opened and the previous cassette removed at block 4110. Blocks 4102, 4104, 4106 may be repeated until all volumetric calibration cassettes have been used for data collection. Depending on the embodiment, there may be fewer than ten cassettes (eg, 4-5), but larger numbers (eg, a dozen, two dozen, or more) may be used. In a particular example, a volumetric calibration cassette can be constructed in 1 mL increments from having a substantially empty pump chamber to having a substantially full pump chamber. Alternatively, the volume calibration cassette can be incremented by a percentage of the total volume of the pump chamber. Starting from empty, an additional 5% or 10% of the total fill can be added to each volume calibration cassette. Typically, the volume calibration cassettes used may include at least one volume calibration cassette that is a typical single-use cassette with a fully delivered and fully filled pump chamber. Multiple (eg, 2-3 or more) volume calibration cassettes representing single-use cassettes with pump chambers partially filled to different volumes can also be used. In some embodiments, volumetric calibration cassettes having volumes outside the pump stroke volume range of disposable pump cassette 24 may also be used. For example, a volumetric standard cassette having a pump chamber volume representing a condition greater than empty can be used. Such volumetric standard cassettes, for example, are designed to produce a control chamber volume of about 110-150% (e.g., 125%) of the expected volume of the volumetric standard cassette representing the empty disposable cassette 24 pump chamber 181. can be done. Such a volumetric calibration cassette may help ensure that the derivative of the constructed correction curve does not increase or decrease rapidly outside the normal pumping range of the disposable pump cassette 24.

At block 4108, if additional volumetric calibration cassettes are not present, one or more correction curves may be generated at block 4112. This correction curve may serve as a cycler-specific calibration equation that corrects for volumetric errors that may be specific to that cycler. Because a standardized set of volumetric calibration cassettes is used, this cycler-specific correction curve may correct for volumetric errors caused by the cycler itself. Contributions from disposable cassette variations may not be introduced. If correction curves are generated for positive and negative FMS, two correction curves may be generated at block 4112. Also, correction curves may be generated for stroke-related measurement delivery and stroke-related measurement filling. A correction curve can be generated for each pump pressure pair used by the cycler. Furthermore, arbitrary correction curves can be generated for each individual control room. A correction curve may be generated based on the associated measured control chamber volume taken by the cycler 14 and the known volume represented by the pump chamber region of the volumetric calibration cassette. In some embodiments, if the correction is greater than a certain magnitude, cycler 14 may flag it for further inspection. If multiple control room readings are taken from each volumetric calibration cassette for a particular set of conditions, these readings are averaged together or otherwise in order to arrive at a single value. be analyzed. These single values can be used to generate a correction curve. A straight line or curve, such as a best-fit polynomial, can be approximated via the values contained in the data set (e.g., determined by linear or non-linear regression analysis, such as least squares regression). In other embodiments, all measurements collected for a particular set of conditions may be fit to a line or curve (e.g., determined by linear or nonlinear regression analysis, such as least squares regression). In some embodiments, the line or curve may be subject to various constraints. For example, a set of restrictions may apply to the allowable derivatives of a line or curve in a particular region. For example, the area of the line or curve just outside the data points collected from the volumetric standard cassette may be subject to such constraints. The differential value may need to be within a predefined range. Such a constraint may be applied, for example, to a region of the line where the volume calibration cassette exceeds the expected pump chamber 181 volume of the modeled disposable cassette 24 by 1-5 ml. Zero crossings of lines or curves may be subject to such constraints.

Before generating a single value from each set of measurements in each specific set of conditions, or before generating a line or curve, the collected measurements are analyzed to some predefined criteria. It is possible to determine the suitability of For example, readings may be checked to ensure that they have an expected distribution, such as a normal distribution, and an error may be generated if a mismatch is detected. In some examples, a standard deviation or other variability measure may be calculated for each set of measurements and compared to an acceptance threshold. If a threshold is exceeded, an error may be triggered. Alternatively, if the collected data is determined to be unfavorable, cycler 14 may prompt the user to reinstall the volumetric standard or calibration cassette so that the data can be recollected. There may be an upper limit on the number of recollection attempts allowed before an error is triggered. Once generated, the correction curve may be stored in memory of cycler 14 at block 4114 as an equation or potentially a look-up table.

Referring to FIG. 75, a graph 4120 illustrating an exemplary calibration curve for a control room of cycler 14 is shown. As shown, several points 4122A-E are plotted on graph 4120. Each point 4122A-E represents the known air volume that should have been measured in the cycler control chamber by the particular volume calibration cassette relative to the raw control room volume, as measured by the cycler for the particular volume calibration cassette. plotted for. As shown, exemplary data from five different exemplary volumetric calibration cassettes are included. Depending on the embodiment, more or fewer volumetric calibration cassettes may be used and the number of data points on the graph will reflect this. The raw value represented by each point 4122A-E represents the average number of measurements that would be made for each particular volumetric calibration cassette. If a disposable cassette 24 is used, a component of the control system of the cycler 14 (e.g., a processor or FPGA) inputs the raw measurement data into this equation to arrive at a more accurate determination of the control chamber volume. be able to. This can increase the accuracy of fluid movement accounting by control system 16 as cycler 14 pumps fluid through disposable cassette 24.

As shown in FIG. 76, in some embodiments, once the cycler 14 is calibrated, the calibration curve of the cycler 14 may be further modified. The calibration curve may be adjusted to an improved calibration curve, for example, based on data collected from several disposable cassettes 24 used in the cycler 14 that were precalibrated with volumetric calibration cassettes. This allows aspects of the disposable cassette 24, such as the sheet 15, to be accounted for in the final improved calibration curve, which may help to further increase the accuracy of the volume transfer measurements performed by the cycler 14. It can be done. This refinement may be done once in certain embodiments. Alternatively, calibration curve refinement may be lot-specific and updated for each treatment when a new disposable cassette 24 is installed in the cycler 14. Therefore, in any case, the final calibration curve used by cycler 14 may be comprised of cycler 14-specific corrections and disposable cassette 24-related corrections.

FIG. 76 shows an example graph 4190 showing several calibration curves 4192, 4194, 4124 that may be used by cycler 14. Specifically, a cycler 14 specific curve 4124, a disposable correction curve 4194, and a final correction curve 4192 are plotted. The final correction curve 4192 can be determined via the following equation in certain embodiments.
V _Final = V _{cyclercorrected} (V _m ) + V _{disposable corrected} (V _m )
where V _{cyclercorrected} is the raw measured control room capacity (V _m ) corrected for the 14 error contribution of a particular cycler, and V _{cyclercorrected} is the raw measured control room capacity (V m ) corrected for the single-use-related error contribution. The measured control room capacity of the process. As a result, V _Final is an improved calibration curve that corrects for volumetric errors associated with cycler 14 and disposable pump cassette 24. Depending on the embodiment, V _{cyclercorrected} can be an equation such as AV _m ³ +BV _m ² +CV _m +D. where V _m is the cycler's raw control room measurements and A, B, C, and D are the coefficients determined to produce the best fit based on the calibration data. Again depending on the embodiment, V _{disposable corrected} can be an equation such as EV _m ³ +FV _m ² +GV _m +H. where V _m is the cycler's raw control room measurements and E, F, G, and H are the coefficients determined to produce the best fit based on the calibration data. Although both V _{cyclercorrected} and V _{disposablecorrected} are shown as cubic equations above, in other embodiments they may be higher or lower order polynomials. In some embodiments, the selected polynomial may be the one that produces the highest R ² value from a selection of linear equations, eg, up to an optimal polynomial of order 5.

In other embodiments, the final correction curve may be determined differently. In some embodiments, V _Final may be equal to a composite function. The first function may be applied to raw control room volume measurements (V _m ). A second function can then be applied to this result to arrive at a determination of V _Final . For example, in some embodiments, an equation such as:
V _Final = V _{disposable corrected} (V _{cyclercorrected} (V _m ))
can be used.

In such embodiments, the raw measured volume (V _m ) may be fed to a function that yields a corrected cycler volume measurement (V _{cyclercorrected} ), similar to that described above. V _{cyclercorrected} then feeds a function that corrects the contribution of disposable-related errors to provide V _{disposablecorrected} equal to the final volume (V _Final ). V _{disposablecorrected} can be an equation such as EV _{cyclercorrected} ³ +FV _{cyclercorrected} ² +GV _{cyclercorrected} +H. Here, E, F, G, and H are the coefficients determined to produce the optimum. As mentioned above, the use of cubic equations is exemplary and higher or lower order polynomials may be used in other embodiments.

Referring to FIG. 77, a flowchart 4170 is shown illustrating some example actions that may be used to improve the calibration curve of cycler 14. At block 4172, a number of cyclers 14 that have been previously calibrated with a set of capacitance measurement standards may be selected. The selected cyclers 14 may be selected such that they meet certain predefined criteria. For example, disposable cassette 24 may be placed in a pre-calibrated cycler 14 and data may be collected. This data may be screened to identify groups of cyclers 14 that are operating with some predefined measurement accuracy. Predefined dispersion criteria (such as acceptable standard deviations) ensure that the measurements of a cycler 14 for any particular set of test conditions are such that all cyclers 14 are similar and representative of a typical cycler 14 unit. may be imposed.

At block 4174, several disposable pump cassettes 24 may be tested using the cycler 14, and data from the testing may be collected at block 4176. The tested disposable pump cassettes 24 may be selected from a plurality of different manufacturing lots (eg, ten or more). Additionally, a large number (eg, tens) of disposable pump cassettes 24 may be selected from each lot. These disposable pump cassettes 24 command the pumping of various volumes of fluid from the reservoirs and measure measurements from the cycler 14 collected during the transfer of these volumes with the results determined by the scales monitoring the reservoirs. can be tested by comparing the resulting weight delta.

At block 4178, the data may be combined. This can be done in various ways. For example, all raw data points can be combined. These data points can be pairs that include the volume transferred by the cycler 14 and the measured volume displaced from the reservoir (e.g., converted from the weight delta on the scale using density). Alternatively, data collected for a particular disposable pump cassette 24 can be analyzed and the output of the analysis for each disposable pump cassette 24 can be combined. For example, a correction curve for each disposable pump cassette 24 may be generated from raw data collected using that disposable pump cassette 24, and each of these correction curves may be combined.

At block 4180, a correction curve may be generated using the combined data. This correction curve can be used to improve the calibration curve generated using the volumetric standard cassettes of each cycler 14 in block 4182. Accordingly, an improved calibration curve can be created that takes into account errors specific to a particular cycler 14 and errors due to aspects common to disposable pump cassettes 24.

As mentioned elsewhere herein, cycler 14 can operate using a number of different calibration curves. For example, cycler 14 may use one of a set of delivery calibration curves when performing a delivery stroke. The particular delivery curve used can be determined based on the pump pressure used for that delivery stroke. The same applies to the filling stroke. Each of these calibration curves can be modified based on data collected from disposable pump cassette 24 in the manner described above to create an improved calibration curve.

Referring to FIG. 78, a flowchart 4150 depicting several example actions that can be used to refine the calibration curve of a particular cycler 14 based on information related to the disposable cassette 24 that is about to be used in the impending treatment. It is shown. As shown, calibration data may be collected for a particular manufacturing lot of disposable pump cassettes 24 at block 4152. This may be done similarly as described above in connection with FIG. 77. At block 4154, this data may be stored in a database and associated with the manufacturing lot's unique identifier. At block 4156, the cycler may determine the unique identifier of the manufacturing lot of the cassette that is to be used in the impending treatment. In some embodiments, cycler 14 may prompt the user to enter a lot identifier contained in disposable cassette 24, an overpack of set 12, or other portions of set 12. This information may be entered into the cycler 14's user interface or touch screen display. In some embodiments, an identifier (eg, a coded identifier such as a barcode, data matrix, QR code, RFID, etc.) may be included in the cassette 24, overpack, or part of the set 12. The cycler 14 is configured to scan for this identifier using a scanning device included as part of the cycler 14 or attached to the cycler 14 as an auxiliary device via a connection port such as a USB port, an RS-232 port, etc. You can prompt the user. In embodiments where cycler 14 includes an automatic ID assembly, the assembly's imager can be used to collect data from the identifier. Refinement data associated with the lot identifier may then be collected from the database by cycler 14 at block 4158. In certain examples, cycler 14 may collect this data from a server via a wireless or wired network or Internet connection. At block 4160, the cycler may generate an improved calibration curve using the improved data associated with the 24 lots of disposable cassettes. This can be done as described elsewhere herein. At block 4162, disposable cassette 24 may be installed in cycler 14 and treatment may be initiated using the improved calibration curve.

Referring to FIG. 79, a flowchart 4130 is shown illustrating some example actions that may be used to test a manufacturing lot of disposable cassettes during manufacturing 24. As shown, at block 4132, cycler 14 may be calibrated using a number of volumetric standard cassettes, as described elsewhere herein. Optionally, improvements to the cycler 14 calibration curve may also be applied as described elsewhere herein. A manufacturing lot of disposable pump cassettes 24 may be manufactured at block 4134. Disposable pump cassettes 24 from the production lot may be placed into the calibrated cycler at block 4136. The cycler may command the pumping of a predetermined measured amount of fluid through the disposable set. The weight of the fluid reservoir may then be monitored at block 4138. Therefore, several measurement pairs may be collected. One member of the pair may be a volume measurement of a particular volume movement performed by the cycler 14, and the other may be a measurement of the weight change in the reservoir resulting from that volume movement. A comparison between each measurement pair may be performed at block 4140. Weight data can be converted to volume using fluid density during comparison. This comparison may produce a deviation value between the calibrated cycler's 14 measured transfer rate and the actual weight-determined transfer rate from each data pair. Since the errors due to the cycler have been calibrated, the deviation should be due to variations due to the disposable pump cassette 24. If the cycler volume measurement and weight data pair does not match within a predetermined tolerance at block 4142, the production lot may be flagged from further testing or investigation at block 4144. Alternatively, the lot may be rejected. If the cycler volume measurements and weight data match at block 4142, an indication that the lot passes inspection may be generated at block 4146. In some embodiments, a certain number of pairs may need to be exceeded before the lot. A flag is set at block 4144.

In some embodiments, multiple disposable pump cassettes 24 from a manufacturing lot may be tested. The deviation data from each of the disposable pump cassettes 24 may be checked for agreement with predefined tolerance thresholds, as just described. Additionally, the data can be checked to ensure that there is an expected level of distribution or dispersion among the disposable pump cassettes 24, and if the data is missing, the lot can be flagged.

Head Height Sensing In some situations, it may be useful to determine the height position of the patient relative to the cassette 24 or other portions of the system 10. For example, in some situations, a dialysis patient may sense a "pull" or other movement due to fluid flow. Entering or exiting the patient's abdominal cavity during filling or emptying operations. To reduce this sensation, cycler 14 can reduce the pressure applied to patient line 34 (see, eg, FIG. 1A) during fill and/or drain operations. However, in order to properly set the pressure in the patient line 34, the cycler 14 determines the height of the patient relative to the cycler 14, the heater bag 22 (see, e.g., FIG. 1A), the drain, or other parts of the system. be able to. For example, when performing a filling operation, if the patient's peritoneal cavity is located 5 feet above the heater bag 22 or cassette 24, the cycler 14 will be placed higher in the patient line 34 to deliver dialysate than in the patient. You may need to use pressure. The abdominal cavity is located 5 feet below the cycler 14. The pressure can be regulated, for example, by alternately opening and closing a binary air source valve at variable time intervals to achieve a desired target pump chamber pressure. The average desired target pressure may be, for example, keeping a valve open when the pump chamber pressure is below the target pressure by a specified amount, and keeping the valve open when the pump chamber pressure is above the target pressure by a specified amount. It can be maintained by adjusting the time interval when the valve remains closed. . Adjustments to maintain full stroke volume delivery can be made by adjusting pump chamber filling and/or delivery time. When using a variable orifice source valve, the target pump chamber pressure can be reached by changing the orifice of the source valve in addition to the timing of the opening and closing intervals of the valve. To adjust the patient position, cycler 14 temporarily stops pumping fluid and routes patient line 34 to one or more pump chambers 181 (see, e.g., FIG. 3) within cassette 24 ( It can be left in open fluid communication (eg, by opening the appropriate valve port 24 in the cassette). However, other fluid lines can be closed, such as the upper valve port 192 of the pump chamber 181 (see, eg, FIG. 6). In this state, the pressure in the control chamber of one of the pumps can be measured. As is well known in the art, this pressure is correlated to the height of the patient's "head" and can be used by cycler 14 to control the pressure of fluid delivery to the patient. A similar approach can be used to determine the "head" height of heater bag 22 (as it is commonly known) and/or solution container 20. This is because the head height of these components can affect the pressure required to pump fluid in the proper manner. An example of a head height detection and pressure adjustment method is described in Gray et al., U.S. Pat. and is incorporated herein by reference in its entirety.

Although head height detection determination can be used in a variety of applications, and the head height detection described herein can be generalized to any cassette-based pump system, the present specification in connection with a dialysis cycler is Write it down in the book. Such determinations can be made multiple times, for example, immediately after cycler priming, before fluid transfer to or from the patient, or when altered (eg, decreased) flow conditions are detected. Head height sensing can also be performed simultaneously with fluid transfer through another chamber of the pump cassette. Head height detection can be performed simultaneously for multiple locations of interest within the system. The layout of the fluid bath within the cassette can be arranged to facilitate this. For example, two locations of interest within a system where simultaneous measurements or measurements and simultaneous volume transfers are desired may communicate with different fluid baths. The location of interest may also have dedicated fluid pathways to facilitate these simultaneous actions. Head height detection may be particularly useful when used in cyclers that mix dialysate instead of using dialysate from pre-mixed bags. For example, detecting head height can confirm that the component of interest is in the expected location. This allows a series of assumptions to be made about the behavior of the air in the pump chamber, since the air in the pump chamber may be in different states of compression due to differences in source head height. This may improve the accuracy of mixing and general volumetric transfer, as the volumetric displacements calculated by the cycler are captured with more robust reliability.

In embodiments configured to perform continuous flow rate and stroke displacement estimation (see, e.g., FIGS. 56-62), the pump membrane of seat/membrane 15 or seat 151 (see, e.g., FIG. 4) accurately may be placed. Both positive and negative head height can be measured repeatedly over the maximum detection range. The use of a cassette 24 with a pre-formed pump seat 151 that is loose or displaces without substantial extension throughout the stroke may provide additional benefits. The target position of the pump seat 151 may be an intermediate position or state between displacement extremes of the pump seat 151 (e.g., a position of the pump seat 151 where the pump chambers 181A, B are fully filled and fully delivered). . This may enable a repeatable single head height determination process to reliably detect head heights at locations of interest.

Maximized detection range means that the range is most comprehensive or fully inclusive of the expected head height for the location of interest (e.g., patient, heater bag 22, source bag, other source components). may be selected to be. In a particular example, the maximized detection range may be a range that allows detection of maximum positive and negative head heights of approximately the same absolute value (eg, within a few mm of each other). Depending on the location of interest, the position of the pump chamber seat 151, and thus the detection range, can be adjusted to support detection of a wider range of either positive or negative head heights.

Referring now to flowchart 6480 shown in FIG. 80, at block 6482, controller or control system 16 of cycler 14 may determine a target position of pump seat 151 (see, eg, FIG. 4). The position target of pump seat 151 may also be a predetermined position. In some embodiments, target locations may be predetermined for each of several locations of interest. The target position used may be relative to where the height of the head is determined.

At block 6484, the controller may command cycler 14 to begin a pumping stroke. The pumping stroke may be a filling stroke or a delivery stroke, depending on the starting position of the pump seat 151 relative to its target position. Stroke displacement, or position of pump seat 151, may also be monitored during the stroke at block 6484. Again, this can be accomplished as described in connection with Figures 56-62. If the controller determines at block 6486 that the pump seat 151 is at its target position, the stroke may be stopped at that time by the controller at block 6488. Optionally, volumetric measurements including pressure equalization of the control chamber 171B volume, whose pressure is known, using a known reference volume at a known pressure to ensure that the pump seat 151 is in the target position. can be executed.

At block 6490, the pump chambers 181A,B may be isolated by closing the inlet/outlet cassette fluid valves 190, 192 (see, eg, FIG. 6) to/from the pump chambers 181A,B. The pressure applied to the pump chamber seat 151 may also be vented at block 6490. Control rooms 171A,B may be vented to a vent reservoir, such as the ambient atmosphere. Once the control chambers 171A,B are equal to the vent reservoir, the control chambers 171A,B may be isolated. A first pressure in the control chambers 171A,B may be measured at block 6492.

At block 6494, various fluid valves in the cassette 24 may be opened to establish fluid communication between the pump chambers 181A, B and the target location. At block 6496, pressure equalization between the control fluid in the control chambers 171A,B and the fluid in the pump chambers 181A,B may occur. In some embodiments, block 6494 may allow a predetermined period of time to pass during which pressure equalization occurs. Alternatively, at least one pressure sensor in communication with the control chamber 171A,B fluid can be monitored. In the latter case, block 6496 may end if the sensor data indicates that the pressure in control chambers 171A,B is relatively stable. For example, block 6496 may end when the pressure does not go out of range by more than a certain amount or for a certain period of time.

Next, the head height at the location of interest may be determined at block 6504. The head height can be determined by relating the density, acceleration of the fluid due to gravity, and pressure at the end of block 6496 to the head height of the component. Are interested. The height of the head may be equal to the pressure (density * acceleration due to gravity) at the end of block 6496. In some embodiments, the calculated head height may be checked against tolerances to ensure that system 10 is properly set up. If the head height is within an acceptable range at block 6506, the pump pressure may be adjusted to compensate for the head height at block 6508, as described above. If the head height is not within an acceptable range at block 6506, an alert may be generated by the controller for display on the GUI of cycler 14 at block 6510.

Referring back to block 6482, in some embodiments, multiple models may be used to determine a target location based on a desired maximized detection range. For example, a different model may be used if the time required for the pressures in the control chambers 171A,B and pump chambers 181A,B to equalize is above or below a threshold. The first model can be used if: In the above case, the second model can be used. In some embodiments, additional models and thresholds may be included. The first model may be an isothermal model and the second model may be an adiabatic model. Model selection can be determined based on flow rates from other parts of the treatment or from before the treatment. Alternatively, one of the first or second models can be used first. If warranted by the pressure equalization time, the controller can rerun the head height determination.

The first model may operate based on the following example equation:
P _f = (P _i (V _{con, i} ))/V _{con, f} )
Here, P _f is the final pressure in the control chambers 171A, B after equalization in block 6469, P _i is the first pressure from block 6492, and V _con,i is the final pressure when the pump seat 151 is at the target position. V con,f is the volume of the initial control chambers 171A, B when the V _con,f is the volume of the final control chambers 171A, B.

The second model operates based on the following example equation:
P _f = (P _i (V _con,i /V _con,f ) ^γ
Here, γ is the heat capacity ratio (eg 1.4).

By assuming that the pump chamber seat 151 moves from the target position to an extreme displacement, these models can be used to determine the target position based on the desired maximized detection range. For any target pump seat 151 position (and thus V _con,i ), a head height sensitivity range can be determined. P _i may be known (eg, set to 101 kPa or measured by a sensor in communication with the surroundings). By assuming that the pump seat 151 goes into extreme movement, the value of V _con,i can also be known. From this, the pressure change required to bottom out the pump seat 151 with extreme travel, and therefore the head height sensitivity, can be determined. Therefore, based on the observed equalization times, it is possible to select the sheet target position that has the maximum sensitivity range for different head heights.

If the controller determines that the head height is around the edge of the sensitivity range, a second head height detection determination may optionally be made. If the head height is at the end of the sensitivity range, it can be inferred that the pump seat 151 has been displaced at or near extreme movement. In the second head height detection determination, the pump seat 151 position target used may be at the opposite extreme of movement. This improves the visibility of the type of head height (such as positive or negative) detected in the first head height determination, but increases the magnitude.

FIG. 81 illustrates some example actions that may be performed to calculate head height pressure in another embodiment of head height determination. As shown in FIG. 81, at block 8000, the cassette may be primed. At block 8002, the pump chamber may be placed in an initial state where the seat of the chamber can be displaced in response to pressure exerted by the head height of the component of interest. In certain embodiments, the sheet may be placed in a position where it can be displaced in response to either positive or negative pressure. Therefore, if the pump chamber is placed in fluid communication with a system component of interest at either a positive or negative head height with respect to the pump chamber, fluid communication between the chamber and the component of interest. The establishment of this could displace the sheet. This state is sometimes referred to as an intermediate or intermediate stroke state or position. This intermediate position may be determined by the control system as described above, or may be preset.

In situations where the head height of the component of interest is expected to exert a positive pressure on the pump chamber, the pump chamber may be placed in a first bias condition at block 8002. The first bias state may be a state that biases the detection range toward positive head height detection. For example, the pump chamber can remain fully delivered. Similarly, if the head height of the component of interest is expected to be negative relative to the pump chamber, the pump chamber may be placed in a second bias state at block 8002. The second bias state may be a state that biases the detection range toward negative head height detection.

At block 8004, a control chamber associated with a pump chamber used to measure head height may be vented. At block 8006, the cycler's control system may wait for pressure stability within the control chamber to be achieved. At block 8008, a control room associated with the pump room may be isolated. At block 8010, the cycler's control system may wait for the pressure to stabilize within the control chamber. At block 8012, the pump chamber may be placed in fluid communication with the system component of interest. At block 8014, the control system may detect a number of pressure peaks and predict a final pressure in the control chamber (eg, described in more detail below with reference to FIG. 83). At block 8016, the control system may calculate the appropriate head height pressure adjustment based on the final pressure. This regulated pressure can be used for subsequent fluid transfer to or from the component of interest.

As shown in FIG. 82, the consistency check is used in blocks 8006 and 8010 of FIG. can detect gender. Consistency checking may also be used in head height determination as described in connection with FIG. The integrity check may be considered passed if at least one pressure integrity criterion is met during the integrity check. During the integrity check, pressure samples may be taken at set time intervals. In some embodiments, the interval can be set to about 5-30 milliseconds (eg, about 10 milliseconds). These samples can be numerically processed and analyzed for the presence of predefined patterns or characteristics. Once that predefined pattern or characteristic is detected, a signal is generated indicating that stability has been achieved and head height detection determination can continue.

A moving average generated from sensor data can be used to check consistency. For example, the difference (or its absolute value) between two consecutive moving average pressure samples can be calculated. A signal indicating that pressure stability has been achieved may be generated when the pressure difference between the first moving average pressure sample and several subsequent moving average pressure samples consistently approaches zero. In some embodiments, a threshold of less than 0.03 kPa deviation from zero may be used to determine whether the pressure difference is sufficiently close to zero. The number of pressure samples used in the moving average window can be set to five. If pressure stability is not detected within the time delay period, it is determined that pressure stability has not been achieved, an end pressure is recorded, and the process may be repeated. In some embodiments, a lack of pressure stability may trigger an error generated by the control system or after a retry limit is exceeded. In some embodiments, the control system may present an alert on the cycler's graphical user interface asking the user to check the system or stop moving around for a certain period of time.

FIG. 82 is an illustration of an example consistency check. At block 8018, the cassette may be primed. At block 8020, a timer may be started. A timer can be set for the expected time that pressure stability should be achieved. The timer can be between 2 and 6 seconds (eg, 3 seconds) in various embodiments. If it is determined at block 8022 that the timer has elapsed, the control system may execute a predefined error handling protocol at block 8024. For example, the control system may generate an error signal while incrementing a retry counter (which may be limited by a retry cap) or perform a consistency check retry while incrementing.

If the preset time limit has not elapsed, the control system may receive pressure data from one or more pressure sensors monitoring the control room at block 8026. At block 8028, the control system may apply data smoothing to the pressure data. In some embodiments, a moving average may be used to smooth the data. A moving average may use a moving window size of values from 3 to 10 (eg, ~5), but this window size may grow or shrink in relation to the sampling frequency. Any window size that is sufficient to filter out excessive noise can be used.

At block 8030, the control system may determine whether the data complies with a first integrity criterion. If the data does not meet the first consistency criterion, the control system may return to block 8022. The first consistency criterion may be a predefined criterion indicating that the pressure data is relatively stable. For example, in some embodiments a comparison can be made between two consecutive moving average pressure samples. The two consecutive moving average pressure samples may be the moving average of the current sample and the moving average of the previous sample. The comparison can be based at least in part on differences between moving average values of successive pressure samples. In certain examples, the difference or the absolute value of the difference may be determined in the comparison. If a difference is calculated, the first consistency criterion is considered to be satisfied by the controller if the difference (or its absolute value) is approximately zero (e.g., less than 0.025 to 0.02 kPa). obtain. Alternatively, the criterion can be defined as a percentage of the measurable range of head height.

If the data complies with the first integrity criterion, the controller may request the pressure within the control chamber to remain stable on subsequent samplings. For example, the pressure difference may need to remain consistently close to zero for a number of subsequent moving average pressure samples (eg, 3-10). In certain embodiments, the control system determines that pressure stability has been achieved if a comparison performed after each of the five subsequent moving average pressure samples is collected indicates that the pressure is stable. obtain.

As shown in FIG. 82, the control system may initialize a counter at block 8032. The counter may be set to a desired number of moving average sample pressures (eg, 5) required before a determination can be made that the pressure is stable. At block 8034, the control system may receive pressure data from one or more pressure sensors monitoring the control room, and at block 8036, the control system may increment a counter. At block 8038, the control system may determine whether the data complies with a second integrity criterion. For example, the comparison value calculated between the new sample and the previous sample may need to be in the range of approximately 0.00 kPa to 0.05 kPa (eg, less than 0.03 kPa). If the data does not meet the second integrity criterion, the control system may return to block 8022. If the data complies with the second integrity criterion, the control system may determine whether the counter is less than or equal to the preset limit at block 8040. If the counter is less than or equal to the preset limit, the control system may return to block 8034. If the counter exceeds the preset limit, the control system may proceed to determine the head height of the component of interest in block 8042.

As discussed in connection with block 8014 of FIG. 81, when the head height of a component of interest is determined, the determination may be made on an incomplete data set. It is possible to characterize how the system behaves, and based at least in part on that characterization, the final control from the data set is cut off before the final stable pressure is achieved. It may be possible to generate one or more equations that can predict chamber pressure. In certain embodiments, head height determination performed in this manner may take about 20% to 15% or less of the time required to reach a stable pressure. Since treatment setup is generally performed while the user is preparing for bed, minimizing the time required for setup is recognized as an advantage in the field.

This allows rapid head height determination and speeds up pre-treatment checks where head height is determined. It may also be possible to determine the height of the head during treatment, with minimal impact on the treatment itself. Without significantly increasing setup or treatment time, this allows the determination of the head height of the component reservoir of interest to be made redundantly as a self-check, or for multiple readings that may provide greater accuracy. It is also possible to generate an average.

In order to determine the head height using an incomplete data set, the control system may e.g. Data can be analyzed. These expected features and their associated temporal features (e.g., when they occur and/or the time between them) determine the final stable control room pressure after sufficient features have been detected. can be used to estimate. This extrapolated pressure may provide a good estimate of the head height of the component of interest.

For example, in the system 10 shown in FIGS. 1-9, the system 10 can operate similar to an underdamped secondary system when head height determinations are made. In such an example, the feature set may be informed by the ideally expected properties under a damped second-order system. For example, the feature set may include an overshoot pressure peak and an undershoot pressure peak that is less in magnitude than the overshoot peak. The control system 16 of the cycler 14 can detect pressure overshoot and undershoot peaks within the control chamber after the pump chamber is placed in communication with the component of interest. The data associated with these peaks can then be used to estimate the final chamber pressure, greatly speeding up the measurement process.

The data can also be used to determine characteristics of interest other than head height. For example, in certain embodiments, the temporal characteristics associated with the feature set may be used as a measure of resistance within the tube. This may allow determining the length of the fluid line between the cassette and the reservoir component of interest. If line extension accessories are available, the number of line extension accessories in use can be determined based on the temporal characteristics of the feature set. This type of decision may also allow line extension to be used on a wider variety of lines with reduced impact on treatment time. For example, pump pressure to and from the patient can be adjusted to provide slower fluid movement to increase patient comfort. The pump pressure used may be selected based on temporal characteristics to produce the desired pressure on the patient side of the line. This allows pressure to be kept at or near maximum pump pressure as resistance in the line leads to a drop in pressure on the patient side. As a result, increased fluid transfer time can be avoided if a patient line extension is used. This may allow for a longer residence period and more clearance of metabolic waste from the patient over the same programmed treatment time.

The temporal characteristics of the feature set can also be used to determine whether a flow impedance is present in the flow path between the cassette and the reservoir component of interest. In certain embodiments, these temporal features can be used to determine whether an occlusion or partial occlusion is present. Alternatively, these temporal features may be collected to help inform occlusion or partial occlusion decisions.

FIG. 83 includes a flowchart detailing some example actions that may be performed during head height determination. At block 8044, the cassette may be primed and the pump chamber seat placed in an initialized position. At block 8046, a timer may be started. A timer can set the expected time that the functionality of the feature set should be observed. The timer can be between 2 and 6 seconds (eg, 3 seconds) in various embodiments. If it is determined at block 8048 that the timer has elapsed, the control system may execute a predefined error handling protocol at block 8050. For example, the control system may increment a retry counter (which may be limited by a retry cap), generate an error signal, or perform a retry of the head height determination.

When performing head height sensing, the control system can receive pressure data from at least one pressure sensor monitoring a control chamber within block 8052. In certain embodiments, data collected in the initial time window may not be used for analysis to minimize noise concerns. This time window may be up to about 1 second (eg, about 0.3 seconds), although this value may vary from embodiment to embodiment. At block 8054, the control system may apply data smoothing to data received from the at least one pressure sensor. Data smoothing may be similar to that described in connection with block 8028 of FIG. At block 8056, the control system may compare several (eg, two) consecutive moving average pressure samples to determine whether the first condition exists. In the exemplary embodiment shown in FIG. 1, in FIG. 83, the control system calculates the difference (or its absolute value) between these moving average samples at block 8056. At block 8058, the system may determine whether a first condition exists (eg, whether the difference is less than a predefined limit). The predefined limit may be, for example, between 0.005 and 0.04 kPa (eg, 0.025 kPa). In the example of FIG. 83, if the difference is greater than or equal to the predefined limit, the control system may return to block 8048. If the difference is less than a predefined limit, the control system may compare the maximum value of the moving average sample window and the current moving average pressure sample to determine whether a second condition exists. For example, FIG. 83 calculates the difference (or the absolute value of the difference) between the maximum moving average sample pressure and the current sample pressure at block 8060. As shown in FIG. 83, if a peak has not yet been detected at block 8062, the control system may determine whether the difference is less than a second predefined limit at block 8064. The second predefined limit may be less than the first predefined limit described above with respect to block 8058. In some embodiments, the first peak pressure may be set at block 8066 if the difference is between about 0.000 kPa and 0.020 kPa (eg, less than about 0.005 kPa). If the system is characterized as a damped second-order system, the first peak may be an overshoot peak. This pressure peak can be set to the current moving average pressure sample, or perhaps the average of the current moving average pressure sample and the previous sample. The time it takes to reach pressure overshoot is also listed in block 8066. The control system may then return to block 8048. If the difference is not less than a second predefined limit at block 8064, the control system may also return to block 8048.

When the first peak is detected and the control system reaches block 8062 again, the control system may proceed to block 8068. At block 8068, the control system may determine whether the time from the first pressure peak is greater than a predefined amount of time. This predefined time may be an empirically determined time expected before the next peak occurs. For an ideal damped second-order system, this time should be approximately the same as the time required to reach the first peak. For example, the predefined time can be set to a value (e.g., 0.1 to 0.4 seconds) that helps account for deviations from an ideal system from the time required to reach the first peak. Can be set equal to the subtracted value. If the predefined time has not yet elapsed, the control system may return to block 8048. Once the predefined time period has elapsed, the control system may determine at block 8070 whether the current pressure magnitude is greater than that detected for the first peak. If the current pressure magnitude is greater than that detected at the first peak, the control system may return to block 8066 and reset the first peak as the current pressure. Again, elapsed time may also be recorded. However, if the current pressure is less in magnitude than the first peak pressure, the control system may define the second peak pressure as the current pressure at block 8072. The elapsed time until detection of the second peak pressure may also be recorded. At block 8074, the control system may determine a percent overshoot. The overshoot rate can be determined using the following formula.
Overshoot percentage = (1-(P ₁ /P ₂ )-α)
Here, P ₁ is the first peak pressure, P ₂ is the second peak pressure, and α is a correction factor that can be determined empirically. Correction factors can be used to adjust for deviations from the ideal quadratic system.

At block 8076, the control system may calculate the height of the head. In some embodiments, the head height itself may not be calculated, but a related value such as pressure due to head height may be calculated (or both may be calculated). This can be determined by predicting the final pressure that would have existed if the pressure had stabilized after detection of the peak. The final pressure P _Final can be determined using the following equation:
P _Final = P ₁ / (1 + overshoot percentage)

The starting pressure in the pump chamber can then be subtracted from the final pressure to determine the pressure due to head height. If desired, this pressure can be converted to head height in units of distance based on acceleration due to gravity, density of the liquid, and pressure values described elsewhere herein. .

In FIGS. 84-86, it is observed that in some embodiments, a volume displacement measurement calibration with respect to the head height determined for a given source or tination may be desirable. Without being bound by any particular theory, the air within the pump chamber may be in various states of compression due to differences in source head height. This may have a slight impact on the volume measurements collected by cycler 14. Additionally, the position of pump seat 151 and gasket 148 may vary slightly depending on head height, which may affect volume measurements.

Figures 84 and 85 show representative views of the pump chamber 181 after completing a destination delivery stroke at different head heights. For purposes of illustration, the figures show the major difference in the position of the pump seat 151 between FIGS. 84 and 85. As shown in FIG. 84, when cycler 14 finishes a destination delivery stroke at a particular high head height, pump seat 151 of cassette 24 seat 15 substantially conforms to the shape of spacer 50 of pump chamber 181. Can match. Gasket 148 mimics or fits the same contour envisioned in cassette sheet 15. Upon completing the delivery stroke to the destination at a lower relative head height (using substantially the same delivery pressure as in FIG. 84), the pump seat 151 advances or bends into the gap between the spacers 50 in the pump chamber 181. I can do it. However, the material of gasket 148 may not match the position of pump seat 151 as closely in this scenario. A similar but generally opposite effect of head height may exist on the fill stroke. As shown above, at the end of the delivery stroke, energy may be stored in non-ideal locations depending on the height of the head. During an FMS procedure (described in more detail elsewhere herein), control chamber 171 is typically vented to atmosphere, filled with a predetermined pressure, and then set to a reference chamber volume and pressure. can be equal. If energy is stored in the system, there may be some movement in pump seat 151 and/or gasket 148 during these pressure changes. This movement may be related to the amount of energy stored in the system at the end of the delivery stroke. This may introduce some error into the volume measurements collected by cycler 14, as this slight movement may affect the volume of control chamber 171. Since this error is predictably related to head height, calibration corrections can be performed based on head height.

The cycler's 14 calibration curve (e.g., any of the calibration curves described above) can be used to improve the calibration used when transferring fluid to and from each source or destination, e.g., based on its head height. Can be adjusted to curves. Therefore, a different calibration curve could potentially be used for each source or tination that communicates with the disposable pump cassette 24.

Referring primarily to FIG. 86, a flowchart 4200 is shown detailing several actions that may be used to determine a calibration curve for a particular head height. At block 4202, a number of cyclers 14 calibrated with volumetric standard cassettes may be selected. These cyclers 14 may be selected based on criteria similar to those described in connection with block 4172 of FIG. 77. At block 4204, a disposable set 24 may be placed in each cycler 14. The reservoir associated with each cycler 14 may be positioned at a predetermined head height relative to the cycler 14 at block 4206. At block 4208, the control system 16 of each cycler 14 may command the pumping of a volume of fluid using the attached disposable set 24. The amount pumped may be common to all cyclers 14 and may be prespecified. Cycler 14 may perform a volumetric measurement of the pumped fluid at block 4208. Also, at block 4208, the scale may be monitored to record the resulting weight delta as the volume of fluid is pumped through the disposable cassette 24 by the cycler 14.

At block 4210, the volumetric measurements and associated scale data collected from each cycler 14 may be combined. For example, all raw data points can be combined. These data points can be pairs that include the transferred volume measured by a particular cycler 14 and the corresponding measured volume displaced from the reservoir (e.g., converted from the weight delta on the scale using density). . Alternatively, data collected from a particular cycler 14 can be analyzed and the output of the analysis of individual cycler data sets can be combined. For example, a correction curve for each cycler 14 at its predefined head height may be generated from raw data associated with that cycler 14. Each of these correction curves may then be combined.

At block 4212, a single correction curve may be generated using the combined data. This correction curve can be used to refine the calibration curve generated using the volumetric standard cassettes of each cycler 14 in block 4214. This curve may be used by the cycler 14 when transferring fluid to and from this head height location. Several head height calibration curves can be generated in the same way. Additionally, at each head height, data sets can be collected for different pump pressure pairs used by the cycler 14, as well as positive and negative FMS measurements. Each data set can be used to make specific refinements to the calibration curve. During treatment, the final calibration curve used can be selected to match the detected head height, pump pressure, and type of FMS measurement being performed (positive or negative).

The final correction value can be determined via a composite function, although other equations are possible. The first function may be applied to raw control room volume measurements (V _m ). A second function can then be applied to this result and the resulting values can be further input into a third function to arrive at a VFinal decision. For example, in some embodiments, an equation such as:
V _Final = V _HeadHeight (V _{disposable corrected} (V _{cyclercorrected} (V _m ))) is a function of the raw measured control room volume (V _m ) where V _{cyclercorrected corrects} for the error contribution of 14 for a particular cycler; V _{disposablecorrected} is a function of the cycler-corrected measurement volume, correcting the contribution of disposable-related errors, and V _HeadHeight is a function of the disposable corrected measurement volume, correcting the contribution of errors related to head height. Correct. Alternatively, V _{disposablecorrected} could be a function of V _HeadHeight like this:
V _Final = V _{disposable corrected} (V _HeadHeight (V _{cyclercorrected} (V _m ))).

In other embodiments, V _Final may be determined additively as described in connection with FIG. 76, with a head height correction added to the equation to produce a sum equal to V _Final . Ru.

Various alternatives and modifications may be devised by those skilled in the art without departing from this disclosure. Accordingly, this disclosure is intended to cover all such alternatives, modifications, and differences. Additionally, although some embodiments of the disclosure are illustrated in the drawings and/or discussed herein, the disclosure is as broad as the art permits, and the specification is to be read as well. intended. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. Other elements, steps, methods, and techniques that differ substantially from those described above and/or in the appended claims are also intended to be within the scope of this disclosure.

The embodiments illustrated in the drawings are presented only to demonstrate particular examples of the disclosure. The drawings described are illustrative only and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Additionally, like-numbered elements in the drawings may be the same or similar elements, depending on the context.

When the term "comprising" is used in this specification and claims, it does not exclude other elements or steps. When an indefinite or definite article is used to refer to a singular noun, this includes the plural form of that noun, unless specified otherwise. Therefore, the term "comprising" should not be construed as limited to the items listed thereafter. The scope of the expression "device including items A and B" should not be limited to devices including only components A and B, as other elements or steps are not excluded.

Additionally, terms such as "first", "second", "third", etc., whether used in the description or the claims, are provided to distinguish between similar elements and are not necessarily contiguous. It is not intended to explain historical or chronological order. The terms so used are interchangeable under appropriate circumstances (unless explicitly disclosed otherwise) and the embodiments of the disclosure described herein refer to those described or illustrated herein. It should be understood that other arrangements and/or arrangements can be operated.
The first aspect of the present invention is
A volumetric standard cassette for calibration of cassette-based pump systems, comprising:
a plurality of solid pump chamber regions configured to be hermetically installed within said cassette-based pump system, each having a predefined shape defining a central body and a known volume of the pump chamber region; A volumetric standard cassette that includes a rigid body that is devoid of channels and orifices.
The second aspect of the invention is
A volumetric standard cassette according to aspect 1, wherein the volumetric standard set is metal.
The third aspect of the present invention is
The volumetric standard cassette according to aspect 1, wherein the volumetric standard cassette is machined.
It is a cut.
The fourth aspect of the present invention is
The capacitance measurement standard set is a capacitance measurement standard set according to aspect 1, made from a list of materials consisting of aluminum, steel and plastic.
The fifth aspect of the present invention is
Aspect 1, wherein the capacitance measurement standard set is constructed via a material addition process.
This is a standard set for capacitance measurement.
The sixth aspect of the present invention is
A capacitive measurement standard set according to aspect 1, wherein the central body has a thickness at least half the thickness of the thickest part of the rigid body.
The seventh aspect of the present invention is
The central body is a capacitive standard set according to aspect 1, wherein the central body has a thickness of at least 60% of the thickness of the thickest part of the rigid body.
The eighth aspect of the present invention is
According to aspect 1, the central body has a thickness of 1/2 to 3/4 of the thickest part of the rigid body.
The standard set of capacitance measurements described.
The ninth aspect of the present invention is
The volumetric standard cassette according to aspect 1 does not include a cassette sheet.
It is a standard cassette.
The tenth aspect of the present invention is
A volumetric standard cassette for calibration of cassette-based pump systems, comprising:
a central body that is completely solid and includes a second surface opposite the first surface;
a plurality of walls extending from at least the first surface of the central body and including a peripheral wall and a plurality of inner walls located at a peripheral edge of the central body;
a plurality of solid pump chamber regions, each having a predefined shape defining a known volume of the pump chamber region;
, wherein the volumetric standard cassette is a volumetric standard cassette that cannot pump fluid.
The eleventh aspect of the present invention is
11. The volumetric standard cassette of aspect 10, wherein no sheet is bonded to any of the plurality of walls of the volumetric standard cassette.
The twelfth aspect of the present invention is
11. A volumetric standard cassette according to aspect 10, wherein the first side of the central body is not covered by a cassette sheet and includes the pump chamber area.
The thirteenth aspect of the present invention is
11. The volumetric standard cassette of aspect 10, wherein both the first side and the opposing side of the central body are not covered by a cassette sheet.
The fourteenth aspect of the present invention is
The capacitance measurement standard set is a capacitance measurement standard set according to aspect 10, wherein the capacitance measurement standard set is created from a list of processes consisting of material addition processes, machining, and molding.
The fifteenth aspect of the present invention is
The capacitance measurement standard set is a capacitance measurement standard set according to aspect 10, wherein the capacitance measurement standard set is made from a list of materials consisting of aluminum, steel, and plastic.
The sixteenth aspect of the present invention is
Volumetric measurement according to aspect 10, wherein the opposing surfaces of the volumetric standard cassette are flat.
This is a standard cassette.
The seventeenth aspect of the present invention is
A volumetric standard cassette according to aspect 10, wherein the first side of the volumetric standard cassette includes a plurality of protrusions surrounded by walls of the inner wall.
The eighteenth aspect of the present invention is
A capacity measurement standard set according to aspect 10, wherein the wall has high airtightness.
The nineteenth aspect of the present invention is
A cassette analog of a disposable pump cassette for the calibration of cassette-based pump systems, comprising:
a central body having a first surface and an opposing second surface;
a plurality of sealing ribs on at least the first surface;
a first pump chamber region and a second pump chamber region, each of said first pump chamber region and said second pump chamber region being a selected region of a corresponding pump chamber in said disposable pump cassette. a first pump chamber region and a second pump chamber region having a defined dimensionally stable shape representing a fill volume;
, wherein the first side and the opposing side are open faces, and the cassette analog is a cassette analog incapable of pumping fluids.
The 20th aspect of the present invention is
20. The cassette analog of embodiment 19, wherein the cassette analog is formed of metal.
The twenty-first aspect of the present invention is
20. The cassette analog according to embodiment 19, wherein said central body is completely solid.
The twenty-second aspect of the present invention is
20. The cassette analog of embodiment 19, wherein said midbody lacks pass-through.
The twenty-third aspect of the present invention is
20. The cassette analog of aspect 19, wherein the selected fill amount is the total pump chamber volume of the corresponding pump chamber in the disposable pump cassette.
The twenty-fourth aspect of the present invention is
20. A cassette analog according to aspect 19, wherein the selected fill volume is the empty pump chamber volume of a corresponding pump chamber in the disposable pump cassette.
The twenty-fifth aspect of the present invention is
20. The cap of aspect 19, wherein the selected fill volume is intermediate between a full pump chamber volume and an empty pump chamber volume of a corresponding pump chamber in the disposable pump cassette.
Set analogues.
The twenty-sixth aspect of the present invention is
Cassettes according to aspect 19, wherein opposing surfaces of the volumetric standard cassette are flat.
It is a likeness.
The twenty-seventh aspect of the present invention is
the first side of the volumetric standard cassette includes a plurality of protrusions surrounded by the sealing rib, the plurality of protrusions positioned at positions corresponding to a plurality of valve seats in the disposable pump cassette; , the cassette analog according to aspect 19. It is.
The twenty-eighth aspect of the present invention is
The cassette analog is a cassette analog according to aspect 19, lacking ports, spikes, and attached fluid lines.
The twenty-ninth aspect of the present invention is
A method for calibrating a cassette-based pump system, the method comprising:
sequentially installing a plurality of volumetric calibration cassettes in the cassette-based pump system, each of the plurality of volumetric calibration cassettes including a pump chamber region having a known volume;
using the cassette-based pump system to measure a known volume of a pump chamber region of each of the volumetric calibration cassettes;
of the volumetric measurements made in the cassette-based pump system based at least in part on a known volume for each of the plurality of volumetric calibration cassettes and a corresponding measured volume of the pump chamber region for each volumetric calibration cassette. generating a calibration curve for;
A method including:
The 30th aspect of the present invention is:
Measuring the known volume of the pump chamber region in each of the volumetric calibration cassettes includes taking a plurality of measurements of the known volume of the pump chamber region in each of the volumetric calibration cassettes, and measuring the known volume of the pump chamber region in each of the volumetric calibration cassettes; 30. The method of aspect 29, comprising analyzing the pump chamber region to determine a single value of the volume of the pump chamber region that serves as the corresponding measured volume.
The thirty-first aspect of the present invention is
31. The method of aspect 30, wherein analyzing the plurality of measurements includes averaging the plurality of measurements.
The 32nd aspect of the present invention is:
According to aspect 29, generating the calibration curve includes generating a best-fit equation.
This is the method described.
A thirty-third aspect of the present invention is:
According to aspect 29, generating the calibration curve includes generating a best-fit polynomial.
This is the method described.
The thirty-fourth aspect of the present invention is:
The method according to aspect 33, wherein the best fit polynomial is the third-order polynomial.
The thirty-fifth aspect of the present invention is
As described in aspect 29, generating the calibration curve includes performing a least squares regression.
This is the method described.
The thirty-sixth aspect of the present invention is:
30. The method of aspect 29, wherein generating the calibration curve includes constraining at least one region of the curve to at least one limit.
The thirty-seventh aspect of the present invention is:
Aspects in which the limit is a permissible range of differential values of points along the at least one region.
This is the method described in No. 36.
The thirty-eighth aspect of the present invention is:
30. The method of aspect 29, wherein generating the calibration curve includes imposing constraints on allowable differential values at zero crossings of the calibration curve.
The thirty-ninth aspect of the present invention is
Measuring the known volume of the pump chamber region in each of the volumetric calibration cassettes includes measuring the known volume of the pump chamber region in each of the volumetric calibration cassettes multiple times and Aspect 29, comprising determining compliance with a criterion and analyzing the plurality of measurements to determine a single value of the volume of the pump chamber region serving as the corresponding measured volume. This is the method.
The fortieth aspect of the present invention is:
The method according to aspect 39, wherein the predefined criterion is a predefined acceptable variability.
It is the law.
The 41st aspect of the present invention is:
40. The method of aspect 39, wherein the predefined criterion is an accepted standard deviation.
The 42nd aspect of the present invention is:
30. The method of aspect 29, further comprising refining the calibration curve to a second calibration curve that accounts for volumetric errors due to disposable pump cassettes.
The 43rd aspect of the present invention is:
30. The method of aspect 29, further comprising refining the calibration curve to another calibration curve that accounts for volumetric errors due to fluid source or destination head heights.
A forty-fourth aspect of the present invention is:
A cassette-based pump system,
a fluid handling set including a pump cassette having a flexible membrane covering at least one pump chamber;
Being a cycler,
a mounting location sized to accommodate the pump cassette and position the cassette relative to a control surface;
multiple pressure reservoirs,
a pressure delivery assembly for applying pressure to the pump cassette from the pressure reservoir to pump fluid through the cassette, the control surface, the pneumatic channel, and the control for actuating the flexible membrane and pressure sensor; a pressure delivery chamber, and at least one reference chamber of known volume for measuring the volume of the pump chamber, the pneumatic channel being in selective communication with the pressure reservoir via a plurality of valves. assembly, and
receiving data from the pressure sensor, determining a raw measured volume of fluid pumped via the data, and adjusting the raw measured volume of fluid pumped based at least in part on a cycler-specific calibration equation; controller to
a cycler containing;
It is a system that includes.
The forty-fifth aspect of the present invention is:
45. The system of aspect 44, wherein the controller is configured to adjust the raw measured volume of pumped fluid based at least in part on a cycler-specific calibration equation and a pump cassette volume error calibration equation. be.
The forty-sixth aspect of the present invention is:
The controller is configured to adjust the raw measured volume of pumped fluid based at least in part on a cycler-specific calibration equation, a pump cassette volume error calibration equation, and a head height error calibration equation. , the system according to aspect 44.
The forty-seventh aspect of the present invention is:
45. The system of aspect 44, wherein the cycler-specific calibration equation is an optimal polynomial over a data set of test measurements of a series of volumetric standard cassettes.
A forty-eighth aspect of the present invention is:
Aspect 44, wherein the controller is configured to adjust the raw measured volume of pumped fluid based on a second calibration equation that is a function of the cycler-specific calibration equation.
This is the system.
The forty-ninth aspect of the present invention is:
49. The method according to aspect 48, wherein the second equation is a pump cassette volume error calibration equation.
It is a system.
The fiftieth aspect of the present invention is:
49. The system of aspect 48, wherein the controller is configured to adjust the raw measured volume of fluid pumped based on a third calibration equation that is a function of the second calibration equation.
It is Tem.
A fifty-first aspect of the present invention is:
51. The system of aspect 50, wherein the second equation is a pump cassette volume error calibration equation and the third equation is a head height error calibration equation.
A fifty-second aspect of the present invention is:
51. The system of aspect 50, wherein the second equation is a head height error calibration equation and the third equation is a pump cassette volume error calibration equation.
A fifty-third aspect of the present invention is:
45. The system of aspect 44, wherein the controller is configured to adjust the raw measured volume of the pumped fluid based at least in part on a cycler-specific calibration equation and a second calibration equation. .
A fifty-fourth aspect of the present invention is:
54. The system of aspect 53, further comprising a database of pump cassette volume error calibration equations associated with cassette-associated unique identifiers.
A fifty-fifth aspect of the present invention is:
The cycler further includes a user interface, the controller receiving a cassette-related unique identifier input via the user interface, and communicating with the database to generate a pump associated with the cassette-related unique identifier input. 55. The pump cassette volume error calibration equation configured to obtain a cassette volume error calibration equation and associated with the cassette-related unique identifier input is used as the second calibration equation. This is the system.
A fifty-sixth aspect of the present invention is:
The cycler further includes an imager, the controller determining cassette-related unique identifier data via the imager data and communicating with the database to determine which pump cassettes are associated with the cassette-related unique identifier data. 55. The system of aspect 54, wherein the system is configured to obtain a volume error calibration equation and wherein a volume error calibration equation for the pump cassette associated with the cassette-related unique identifier data is used as the second calibration equation. It is.
A fifty-seventh aspect of the present invention is:
Aspect 4, wherein the fluid processing set includes a coded cassette-related unique identifier.
This is the system described in 4.
A fifty-eighth aspect of the present invention is:
A cassette-based pump system,
A fluid processing set comprising a pump cassette having a flexible membrane covering at least one pump chamber and at least one cassette valve gating fluid communication to a fluid reservoir;
at least one pump control chamber for actuating a portion of the flexible membrane covering the at least one pump chamber; at least one pump control chamber for actuating a portion of the flexible membrane covering the at least one cassette valve; a pressure delivery assembly having at least one pressure sensor in communication with the at least one valve control chamber and the at least one pump control chamber;
a pressure reservoir in selective communication with the at least one pump control chamber and the at least one valve control chamber via a plurality of pressure supply valves; and
receiving data from the at least one pressure sensor, commanding the at least one cassette valve open, and monitoring data from the at least one pressure sensor to identify first and second pressure peaks; a controller configured to calculate a head height of the fluid reservoir based on the first and second pressure peaks;
a cycler comprising;
This is a system that includes
A fifty-ninth aspect of the present invention is:
59. The controller of aspect 58, wherein the controller is further configured to determine a length of a fluid line coupling the fluid reservoir to the cassette based on time data associated with the first and second peaks. It is a system.
The sixtieth aspect of the present invention is:
59. The system of aspect 58, wherein the first peak is an overshoot peak and the second peak is an undershoot peak.
The 61st aspect of the present invention is:
59. The system of aspect 58, wherein the controller is further configured to adjust operating parameters based on the calculated head height.
A sixty-second aspect of the present invention is:
62. The system of aspect 61, wherein the operating parameter is at least one pump pressure.
It is mu.
A sixty-third aspect of the present invention is:
59. The system of aspect 58, wherein the controller is further configured to refine the calibration curve based on the head height.
A sixty-fourth aspect of the present invention is:
59. The system of aspect 58, wherein the fluid reservoir is a dialysate reservoir.
A sixty-fifth aspect of the present invention is:
59. The system of aspect 58, wherein the fluid reservoir is a body cavity of the patient.
A sixty-fifth aspect of the present invention is:
According to aspect 58, the controller is further configured to displace a portion of the flexible membrane covering the at least one pump chamber to an intermediate stroke position before commanding the at least one cassette valve open. This is the system described.
The sixty-sixth aspect of the present invention is:
Aspect 58, wherein the controller is further configured to determine a plurality of extension lines included in a fluid line coupling a fluid reservoir to the cassette based on time data associated with the first and second peaks. This is the system described in .
A sixty-seventh aspect of the present invention is:
59. The system of aspect 58, wherein the controller is further configured to generate an error when the head height exceeds a threshold.
The sixty-eighth aspect of the present invention is
59. The system of aspect 58, wherein the controller is further configured to compare the head height to a predefined allowable head height threshold.
The sixty-ninth aspect of the present invention is
A method of selecting pump pressure for a cassette-based pump system, comprising:
priming a fluid handling set attached to the pump system;
arranging a pump chamber of a cassette of the fluid treatment set to communicate with a reservoir;
detecting a first pressure peak in a control chamber separated from the pump chamber by a membrane;
detecting a second pressure peak within the control chamber;
predicting a final pressure using the first and second pressure peaks;
calculating a pump pressure based on the predicted final pressure;
A method including:
The seventieth aspect of the present invention is:
70. The method of aspect 69, further comprising calculating a head height of the reservoir based on the predicted final pressure.
A seventy-first aspect of the present invention is:
70. The method of aspect 69, further comprising determining a characteristic length of a fluid line coupling the reservoir to the cassette-based time data associated with the first and second peaks. be.
A seventy-second aspect of the present invention is:
70. The method further comprises determining a plurality of extensions included in a fluid pathway coupling the cassette to the reservoir based on time data associated with the first and second peaks. This is the method.
A seventy-third aspect of the present invention is:
70. The method of aspect 69, further comprising generating an error when the predicted final pressure exceeds a predetermined threshold.
A seventy-fourth aspect of the present invention is:
Aspect 69, wherein the method further comprises displacing the membrane to a predetermined initial position.
This is the method described.
A seventy-fifth aspect of the present invention is:
A method according to aspect 74, wherein the predetermined initial position is a position that biases the head height detection range toward positive head height detection.
A seventy-sixth aspect of the present invention is:
75. The method according to aspect 74, wherein the predetermined initial position is a position that biases the head height detection range toward negative head height detection.
A seventy-seventh aspect of the present invention is:
75. The method of aspect 74, wherein the predetermined initial position is the intermediate stroke position.
A seventy-eighth aspect of the present invention is:
70. The method of aspect 69, wherein the method further comprises adjusting a calibration curve of the cassette-based pump system based on the predicted final pressure.
A seventy-ninth aspect of the present invention is:
Aspect 69, wherein detecting the first peak includes calculating a difference between a set of consecutive data points from the at least one pressure sensor in communication with the control room.
This is the method described in .
The 80th aspect of the present invention is:
80. The method of aspect 79, wherein detecting the first peak further comprises applying data smoothing to a set of consecutive data points from the at least one pressure sensor.
It's a method.
The 81st aspect of the present invention is:
80. The method of aspect 79, further comprising identifying a first peak when the difference between successive sets of data points is less than a predetermined limit.
The 82nd aspect of the present invention is:
70. The method of aspect 69, wherein predicting the final pressure includes determining a percent overshoot based on the first and second peaks.
The 83rd aspect of the present invention is:
A method for checking the head height of a reservoir coupled to a cassette-based pump system, the method comprising:
arranging a pumping chamber of a cassette of a fluid handling set installed in a cassette-based pumping system in communication with a reservoir;
detecting a first pressure peak in a control chamber separated from the pump chamber by a membrane;
detecting a second pressure peak within the control chamber;
predicting a final pressure using the first and second pressure peaks;
comparing the predicted final pressure to at least one predetermined threshold;
generating a notification when the predicted final pressure exceeds at least one of at least one predetermined threshold;
A method including:
The 84th aspect of the present invention is:
The method of aspect 83, wherein generating the notification includes generating an error.
The 85th aspect of the present invention is:
84. The method of aspect 83, wherein generating the notification includes generating a screen for display on a user interface of the cassette-based pump system.
The 86th aspect of the present invention is:
The method of aspect 83, wherein generating the notification includes generating an audible noise.
The 87th aspect of the present invention is:
84. The method of aspect 83, further comprising calculating a head height of the reservoir based on the predicted final pressure.
The eighty-eighth aspect of the present invention is
84. The method of aspect 83, wherein the method further comprises determining an overshoot percentage based on the first and second pressure peaks.
The eighty-ninth aspect of the present invention is:
84. The method of aspect 83, further comprising determining a characteristic length of a fluid line coupling the reservoir to the cassette based on time data associated with the first and second peaks. It's a method.
The 90th aspect of the present invention is:
84. The method further comprises determining a plurality of extensions included in a fluid pathway coupling the cassette to the reservoir based on time data associated with the first and second peaks. This is the method.
The 91st aspect of the present invention is:
84. The method of aspect 83, wherein the method further comprises displacing the membrane to a predetermined initial position.
It's a method.
The 92nd aspect of the present invention is:
92. The method according to aspect 91, wherein the predetermined initial position is a position that biases the head height detection range toward positive head height detection.
The 93rd aspect of the present invention is:
92. The method according to aspect 91, wherein the predetermined initial position is a position that biases the head height detection range toward negative head height detection.
The 94th aspect of the present invention is:
92. The method according to aspect 91, wherein the predetermined initial position is the intermediate stroke position.
The 95th aspect of the present invention is:
84. The method of aspect 83, wherein the method further comprises adjusting a calibration curve of the cassette-based pump system based on the predicted final pressure.
The 96th aspect of the present invention is:
Aspect 83, wherein detecting the first peak includes calculating a difference between a set of consecutive data points from the at least one pressure sensor in communication with the control room.
This is the method described in .
The 97th aspect of the present invention is:
84. According to aspect 83, detecting the first peak further comprises applying data smoothing to a set of consecutive data points from the at least one pressure sensor.
This is the method.
The 98th aspect of the present invention is:
84. The method of aspect 83, further comprising identifying the first peak when a difference between successive sets of data points is less than a predetermined limit.
The 99th aspect of the present invention is:
A cassette-based pump system,
A fluid processing set comprising a pump cassette having a flexible membrane covering at least one pump chamber and at least one cassette valve gating fluid communication to a fluid reservoir;
at least one pump control room;
at least one valve control chamber;
at least one pressure sensor in communication with the at least one pump control chamber;
a pressure reservoir in selective communication with the at least one pump control chamber and the at least one valve control chamber via a plurality of pressure supply valves; and
in data communication with the pressure sensor, commanding the at least one cassette valve open, monitoring data from the at least one pressure sensor, identifying first and second pressure peaks; controller configured to predict final pressure based on the second pressure peak;
Cycla, including;
It is a system equipped with.
The 100th aspect of the present invention is:
100. The controller of aspect 99, wherein the controller is further configured to determine a length of a fluid line coupling the fluid reservoir to the cassette based on time data associated with the first and second peaks. It is a system.
The 101st aspect of the present invention is:
100. The system of aspect 99, wherein the first peak is an overshoot peak and the second peak is an undershoot peak.
The 102nd aspect of the present invention is:
100. The system of aspect 99, wherein the controller is further configured to adjust operating parameters based on the calculated head height.
The 103rd aspect of the present invention is:
The system of aspect 102, wherein the operating parameter is at least one pump pressure.
It is Tem.
The 104th aspect of the present invention is:
100. The system of aspect 99, wherein the controller is further configured to refine the calibration curve based on the head height.
The 105th aspect of the present invention is:
100. The system of aspect 99, wherein the fluid reservoir is a dialysate reservoir.
The 106th aspect of the present invention is:
100. The system of aspect 99, wherein the fluid reservoir is a body cavity of the patient.
The 107th aspect of the present invention is:
Embodiments wherein the controller is further configured to displace a portion of the flexible membrane covering the at least one pump chamber to an intermediate stroke position before commanding the at least one cassette valve open. This is the system described in No. 99.
The 108th aspect of the present invention is:
Aspect 99 wherein the controller is further configured to determine a plurality of extension lines included in a fluid line coupling a fluid reservoir to the cassette based on time data associated with the first and second peaks. This is the system described in .
The 109th aspect of the present invention is:
100. The system of aspect 99, wherein the controller is further configured to generate an error when the predicted final pressure exceeds the threshold.
A 110th aspect of the present invention is:
100. The system of aspect 99, wherein the controller is further configured to compare the predicted final pressure to a predefined allowable head height pressure threshold.
A 111th aspect of the present invention is:
A fluid line condition detector, the fluid line condition detector comprising:
a receptacle configured to hold a fluid line that is opaque to ultraviolet light;
optical sensor;
Infrared emitting LED,
UV light emitting LED,
a third LED;
in data communication with a light sensor, when the intensity of the infrared light sensed by the light sensor from the infrared light emitting LED exceeds a predetermined first threshold; a controller configured to determine that a suitable tube is present when below a predetermined second threshold;
, wherein the axis of the infrared emitting LED and the axis of the ultraviolet emitting LED are parallel to each other and also parallel to the axis of the optical sensor.
A 112th aspect of the present invention is:
The fluid line condition of aspect 111, wherein the axis of the infrared emitting LED is an optical axis of the infrared emitting LED, and the axis of the ultraviolet emitting LED is an optical axis of the ultraviolet emitting LED.
It is a detector.
A 113th aspect of the present invention is:
112. The fluid line of aspect 111, wherein the axis of the infrared emitting LED is a mechanical axis of the infrared emitting LED, and the axis of the ultraviolet emitting LED is a mechanical axis of the ultraviolet emitting LED.
In state detector.
A 114th aspect of the present invention is:
The fluid line shape according to aspect 111, wherein the axis of the optical sensor is the optical axis of the optical sensor.
It is a state detector.
A 115th aspect of the present invention is:
The fluid line of aspect 111, wherein the axis of the optical sensor is a mechanical axis of the optical sensor.
is a power-on state detector.
A 116th aspect of the present invention is:
The fluid line of aspect 111, wherein the third LED is the infrared emitting LED.
It is a state detector.
A 117th aspect of the present invention is:
112. The fluid line condition detector of aspect 111, wherein the axis of the third LED is at an angle other than parallel to the axis of the infrared emitting LED and the axis of the ultraviolet emitting LED.
The 118th aspect of the present invention is:
112. The fluid line status detector of aspect 111, wherein the axis of the ultraviolet emitting LED is configured to pass through a central portion of the fluid line installed within the receptacle.
The 119th aspect of the present invention is:
Aspect 111, wherein the receptacle includes a retainer for holding the fluid line.
The fluid line condition detector described in .
The 120th aspect of the present invention is:
112. The controller is further configured to determine that the fluid line is dry when light intensity from the third LED exceeds a predetermined dryness threshold.
Fluid line condition detector.
The 121st aspect of the present invention is:
The controller is configured to determine that the fluid line is primed when the light intensity from the third LED is below a predetermined priming threshold and the predetermined priming threshold is less than the predetermined drying threshold. The flow according to aspect 120, further comprising:
It is a body line condition detector.
The 122nd aspect of the present invention is:
The controller determines that the fluid line is primed when the light intensity from the infrared emitting LED is below a predetermined infrared light threshold and the light intensity from the third LED is below a predetermined priming threshold. 121. The fluid line condition detector of aspect 120, wherein the predetermined priming threshold is lower than the predetermined dryness threshold.
It is.
The 123rd aspect of the present invention is:
The controller is configured to increase the intensity of the ultraviolet light sensed from the ultraviolet light emitting LED by the light sensor when the intensity of the infrared light sensed from the infrared light emitting LED by the light sensor exceeds a predetermined first threshold. indicates that a suitable tube is present in the fluid line condition detector when the intensity of light emitted by the third LED is below a predetermined second threshold; The flow according to aspect 111, configured to determine
It is a body line condition detector.
The 124th aspect of the present invention is:
112. The fluid of aspect 111, wherein the controller is further configured to control the supply of power to the infrared emitting LED, the ultraviolet emitting LED, and the third LED.
It is a line condition detector.
The 125th aspect of the present invention is:
A fluid line condition detector for detecting the presence of a fluid line that is opaque to a first spectrum of light and at least translucent to a second spectrum of light, the fluid line condition detector comprising:
a receptacle configured to hold the fluid line;
optical sensor;
a first LED configured to emit light in a first spectrum;
a second LED configured to emit light in a second spectrum;
a third LED;
in data communication with a light sensor, when the intensity of the first spectrum of light sensed by the light sensor from the first LED is below a predetermined first threshold; the fluid line condition detector is configured to determine that the fluid line is present when the intensity of light of a second spectrum sensed by the optical sensor exceeds a predetermined second threshold; controller and
, wherein the first LED axis and the second LED axis are parallel to each other and also parallel to the optical sensor axis.
The 126th aspect of the present invention is:
126. The fluid line condition detector of aspect 125, wherein the first LED axis is the first LED optical axis and the second LED axis is the second LED optical axis. It is.
The 127th aspect of the present invention is:
126. The fluid line condition of aspect 125, wherein the first LED axis is the first LED mechanical axis and the second LED axis is the second LED mechanical axis. It is a detector.
The 128th aspect of the present invention is:
The fluid line shape according to aspect 125, wherein the axis of the optical sensor is the optical axis of the optical sensor.
It is a state detector.
The 129th aspect of the present invention is:
The fluid line of aspect 125, wherein the axis of the optical sensor is a mechanical axis of the optical sensor.
is a power-on state detector.
A 130th aspect of the present invention is:
Aspects wherein the third LED is configured to emit light in the second spectrum.
125.
The 131st aspect of the present invention is:
126. The fluid line status detector of aspect 125, wherein the axis of the third LED is at an angle other than parallel to the axis of the first LED and the axis of the second LED.
A 132nd aspect of the present invention is:
126. The fluid line of aspect 125, wherein the axis of the first LED is configured to pass through a central portion of the fluid line when the fluid line is installed in the receptacle.
It is a state detector.
The 133rd aspect of the present invention is:
Aspect 125, wherein the receptacle includes a retainer for holding the fluid line.
The fluid line condition detector described in .
The 134th aspect of the present invention is:
Aspect 125, wherein the controller is further configured to determine that the fluid line is dry when light intensity from the third LED exceeds a predetermined dryness threshold.
Fluid line condition detector.
A 135th aspect of the present invention is:
The controller is configured to determine that the fluid line is primed when the light intensity from the third LED is below a predetermined priming threshold and the predetermined priming threshold is less than the predetermined drying threshold. according to aspect 134, further comprising:
Fluid line condition detector. It is.
The 136th aspect of the present invention is:
The controller controls the fluid when the light intensity from the second LED is below a predetermined second light spectrum threshold and when the light intensity from the third LED is below a predetermined priming threshold. Aspect 134, further configured to determine that the line is primed, wherein the predetermined priming threshold is lower than the predetermined drying threshold.
is a fluid line condition detector.
The 137th aspect of the present invention is:
The controller is configured to detect when an intensity of light of the first spectrum sensed by the light sensor from the first LED is below a predetermined threshold; when the intensity of the light of the second spectrum is above a predetermined second threshold and when the intensity of the light sensed by the optical sensor from the third LED is below a predetermined third threshold; 126. The fluid line condition detector of aspect 125, configured to determine that the fluid line is present at the fluid line condition detector.
The 138th aspect of the present invention is:
126. The fluid line condition detector of aspect 125, wherein the controller is further configured to control the supply of power to the first, second, and third LEDs.
The 139th aspect of the present invention is:
126. The fluid line configuration of aspect 125, wherein the first spectrum is an ultraviolet spectrum.
It is a state detector.
A 140th aspect of the present invention is:
A fluid line according to aspect 125, wherein the second spectrum is an infrared spectrum.
It is a state detector.
The 150th aspect of the present invention is:
Aspect 125, wherein the fluid line is transparent to the second spectrum of light.
A fluid line status detector is installed.
The 151st aspect of the present invention is:
A method of detecting the presence of a suitable fluid line within a receptacle of a detector, the method comprising:
emitting a first spectrum of light from a first LED, the fluid line being opaque to the first spectrum of light;
emitting a second spectrum of light from a second LED, the fluid line being at least translucent to the second spectrum of light;
monitoring the intensity of received light using a light sensor located on an opposite side of the receptacle from the first LED and the second LED;
comparing the intensity of light received in the first spectrum to a first threshold;
comparing the intensity of light received in the second spectrum to a second threshold;
determining the presence of a suitable fluid line if the intensity of light in the first spectrum is less than a first threshold and the intensity of light in the second spectrum is greater than the second threshold; ,
A method including:
The 152nd aspect of the present invention is:
152. The method of aspect 151, wherein the first threshold corresponds to substantially no light transmission from the first LED to the optical sensor.
The 153rd aspect of the present invention is:
152. The method of aspect 151, wherein the first spectrum is an ultraviolet spectrum.
The 154th aspect of the present invention is:
152. The method according to aspect 151, wherein the second spectrum is a higher wavelength spectrum than the first spectrum.
The 155th aspect of the present invention is:
152. The method of aspect 151, wherein the second spectrum is an infrared spectrum.
The 156th aspect of the present invention is:
Aspect 151, wherein the fluid line is transparent to the second spectrum of light.
This is the method described.
The 157th aspect of the present invention is:
The method includes generating a notification when the intensity of light in the first spectrum is greater than the first threshold and the intensity of light in the second spectrum is greater than the second threshold. 152. The method of aspect 151, further comprising.
The 158th aspect of the present invention is:
The method of aspect 157, wherein generating the notification includes displaying a notification to reload the fluid line on a graphical user interface.
The 159th aspect of the present invention is:
152. The method of aspect 151, wherein axes of the first LED and the second LED are parallel to each other and parallel to an axis of the optical sensor.
The 160th aspect of the present invention is:
A fluid pump system.
pump and
a displacement volume sensing assembly;
a fluid line status detector having a receptacle for holding the fluid line, at least one optical sensor, and at least one LED;
a fluid transfer set including an output line configured to mate with the receptacle;
at least one fluid source;
a controller in data communication with the fluid line condition detector for powering at least one LED and monitoring an output signal of at least one light sensor when the exit line is installed in the receptacle to detect the configured to determine a light intensity value of the tube, configured to control operation of the pump to prime the output line with fluid from the at least one fluid source, and power to the at least one LED. a controller configured to monitor the output signal and stop operation of the pump when the output signal indicates that the light intensity value falls below a threshold for a primed line; and,
wherein the primed line threshold is calculated by the controller based on the dry tube strength readings.
The 161st aspect of the present invention is:
161. The system of aspect 160, wherein the primed line threshold is calculated by adding a constant to a percentage of the dry tube strength value.
The 162nd aspect of the present invention is:
161. The controller is configured to power the at least one LED multiple times, and the dry tube intensity value is based on a maximum light intensity value output from the light sensor multiple times. It is a system.
The 163rd aspect of the present invention is:
The controller is configured to power the at least one LED multiple times and monitor the output signal to determine a maximum light intensity value, the dry tube intensity value being equal to the maximum light intensity value and The system of aspect 160 is based on at least one limit.
It is.
The 164th aspect of the present invention is:
164. The system of aspect 163, wherein the limit is a minimum value of the dry tube strength value.
It is mu.
The 165th aspect of the present invention is:
161. The system of aspect 160, wherein the controller is further configured to generate a notification when the displaced volume sensing assembly indicates that the displaced volume of fluid is greater than a predetermined threshold. .
The 166th aspect of the present invention is:
166. The system of aspect 165, wherein the controller is configured to continue pumping upon receiving user input from a user interface of the system indicating that the output line is not yet fully primed.
The 167th aspect of the present invention is:
161. The system of aspect 160, wherein the pump is a diaphragm pump.
The 168th aspect of the present invention is:
161. The system of aspect 160, wherein the pump is a pneumatic diaphragm pump.
The 169th aspect of the present invention is:
161. The system of aspect 160, wherein a portion of the pump is included in a fluid transfer set.
The 170th aspect of the present invention is:
The system of aspect 160, wherein the at least one fluid source is a dialysate reservoir.
It is.
The 171st aspect of the present invention is:
161. The system of aspect 160, wherein the at least one LED includes a first LED positioned at an angle to an optical axis of the optical sensor.
The 172nd aspect of the present invention is:
In aspect 171, the at least one LED includes a second LED and a third LED.
This is the system described.
The 173rd aspect of the present invention is:
173. The system of aspect 172, wherein the second LED axis and the third LED axis are parallel to an optical axis of the optical sensor.
The 174th aspect of the present invention is:
A method of priming a fluid line, the method comprising:
installing a fluid line in a receptacle of a fluid line condition detector;
emitting light from at least one LED of the fluid line condition detector a first plurality of times;
monitoring an output signal of a light sensor of the fluid line condition detector and determining a maximum light intensity value based on the first plurality of output signals;
determining a primed line threshold based on the maximum light intensity value;
pumping fluid through the fluid line;
emitting light from the at least one LED of the fluid line condition detector a second plurality of times;
determining that the fluid line is primed when an output signal of the light sensor indicates that light intensity from the LED has exceeded a primed tube threshold;
A method including:
The 175th aspect of the present invention is:
175. The method of aspect 174, wherein installing the fluid line in the receptacle includes seating the fluid line within a channel of the fluid line condition detector.
The 176th aspect of the present invention is:
Aspect 17 wherein the method further comprises comparing the maximum light intensity to a limit and overwriting the maximum light intensity value with the value of the limit if the maximum light intensity value does not comply with the limit.
This is the method described in 4.
The 177th aspect of the present invention is:
Determining the maximum light intensity value based on the output signal includes comparing the light intensity value indicated by the output signal during the first plurality of times to a calibration value to determine a ratio. A method according to aspect 174.
The 178th aspect of the present invention is:
Aspect 177, wherein the calibration value is a light intensity value from the at least one LED output from the optical sensor when no tube is installed in the receptacle.
This is the method.
The 179th aspect of the present invention is:
175. The method of aspect 174, wherein determining the primed line threshold includes adding a constant to a percentage of the maximum light intensity value.
The 180th aspect of the present invention is:
Aspect 17, wherein the second plurality of times occurs during the process of pumping fluid through the line.
This is the method described in 4.
The 181st aspect of the present invention is:
175. The method of aspect 174, wherein emitting light from the at least one LED during the second plurality of times includes emitting light from a first, second, and third LED. .
The 182nd aspect of the present invention is:
175. The method of aspect 174, further comprising ceasing pumping fluid through the line when determining that the fluid line is primed.
The 183rd aspect of the present invention is:
175. The method of aspect 174, wherein the method further comprises monitoring a volume of fluid pumped through the displacement volume sensing assembly.
The 184th aspect of the present invention is:
184. The method of aspect 183, further comprising suspending the pumping of the fluid when the volume of the pumped fluid exceeds a first volume threshold.
The 185th aspect of the present invention is:
185. The method of aspect 184, further comprising restarting the pumping upon receiving user input indicating that the line is not yet fully primed.
The 186th aspect of the present invention is:
185. The method of aspect 184, further comprising inhibiting restart of the pump when the volume of pumped fluid exceeds a second volume threshold.
The 187th aspect of the present invention is:
A fluid pump system comprising:
pump and
a fluid line condition detector having a receptacle, at least one sensor, and at least one illuminator;
a fluid transfer set including an output line configured to mate with the receptacle;
a controller in data communication with a fluid line condition detector, the controller powering at least one illuminator and monitoring an output signal of at least one sensor when an exit line is attached to the receptacle; configured to determine a light intensity value for a dry tube, further configured to control operation of a pump to prime the output line with fluid from at least one fluid source, and powering at least one illuminator. and monitor an output signal to stop operation of the pump when the output signal indicates that the light intensity value has fallen below a primed line threshold that depends on the dry tube intensity value. The system is further configured.
The 188th aspect of the present invention is:
188. The system of aspect 187, wherein the primed line threshold is calculated by adding a constant to a percentage of the dry tube light intensity value.
The 189th aspect of the present invention is:
188. The controller is configured to power at least one illuminator multiple times, and the dry tube light intensity value is based on a maximum light intensity value output from the sensor over multiple times. It is a system.
The 190th aspect of the present invention is:
The controller is configured to power at least one illuminator multiple times and monitor the output signal to determine a maximum light intensity value, the dry tube light intensity value being the maximum light intensity value. and at least one limitation.
The 191st aspect of the present invention is:
The system of aspect 190, wherein the limit is a minimum value of the dry tube light intensity value.
It is Tem.
The 192nd aspect of the present invention is:
The system further includes a displacement volume sensing assembly, and the controller is further configured to generate a notification when the displacement volume sensing assembly indicates that the volume of the displacement fluid is greater than a predetermined threshold. , the system according to aspect 187.
The 193rd aspect of the present invention is:
193. The system of aspect 192, wherein the controller is configured to continue pumping upon receipt of the user input from the user interface of the system indicating that the output line is not yet fully primed. be.
The 194th aspect of the present invention is:
188. The system of aspect 187, wherein the pump is a diaphragm pump.
The 195th aspect of the present invention is:
188. The system of aspect 187, wherein the pump is a pneumatic diaphragm pump.
The 196th aspect of the present invention is:
188. The system of aspect 187, wherein a portion of the pump is included in the fluid transfer set.
The 197th aspect of the present invention is:
188. The system of aspect 187, wherein the at least one fluid source is a dialysate reservoir.
It is.
The 198th aspect of the present invention is:
188. The system of aspect 187, wherein the at least one illuminator includes a first LED positioned at an angle to an optical axis of the sensor.
The 199th aspect of the present invention is:
199. The system of aspect 198, wherein the at least one illuminator includes the second LED and the third LED.
The 200th aspect of the invention is:
199. The system of aspect 199, wherein the second LED axis and the third LED axis are parallel to the optical axis of the sensor.
The 201st aspect of the present invention is:
A capacitive measurement standard set or cycler substantially as shown and described herein.
The 202nd aspect of the present invention is:
Any of the systems, methods, and apparatus shown and described herein.

Claims (29)

A fluid pump system comprising:
pump and
a fluid line status detector having a receptacle for holding the fluid line, at least one optical sensor, and at least one LED;
a fluid transfer set including an outlet line configured to mate with the receptacle;
at least one fluid source;
a controller in data communication with the fluid line condition detector, the controller energizing at least one of the at least one LED multiple times, the exit line being dry and attached to the receptacle ; monitoring an output signal of the at least one light sensor to determine a dry tube light intensity value based on a maximum light intensity value and a limit from the light sensor over a plurality of times; after determining the intensity value, initiating operation of the pump to prime the outlet line with fluid from the at least one fluid source; powering at least one of the at least one LED; a controller configured to monitor the output signal and stop operation of the pump when the output signal indicates that the light intensity value falls below a threshold for a primed line;
wherein the primed line threshold is calculated by the controller based on the dry tube light intensity value. The system of claim 1, wherein the primed line threshold is calculated by adding a constant to a percentage of the dry tube light intensity value. 2. The system of claim 1, wherein the limit is a minimum of the dry tube light intensity value. The system further includes a displacement volume sensing assembly, and the controller is configured to determine whether the volume of displaced fluid before the light intensity value falls below a threshold of the primed line is a predetermined displacement. 2. The system of claim 1, wherein the system is configured to generate a notification when the volume is greater than a threshold value. 5. The controller is configured to continue adjusting operation of the pump upon receiving user input from a user interface of the system indicating that the outlet line is not yet fully primed. system. The system of claim 1, wherein a portion of the pump is included in the fluid transfer set. 2. The system of claim 1, wherein the at least one LED includes a first LED having a first LED axis disposed at an angle non-parallel to the optical axis of the photosensor. The system of claim 1, wherein the at least one LED includes a first LED, a second LED, and a third LED. 9. The system of claim 8, wherein the second LED axis and the third LED axis are parallel to the optical axis of the photosensor. A fluid pump system comprising:
pump and
a fluid line condition detector having a receptacle, at least one sensor, and at least one illuminator;
a fluid transfer set including an outlet line configured to mate with the receptacle;
a controller in data communication with the fluid line condition detector, the controller configured to power at least one of the at least one illuminator, the exit line attached to the receptacle, and configured to be operated by the system; Collecting a plurality of output signal readings from the output signal of the at least one sensor when unprimed (unprimed state) and using the maximum light intensity value from the plurality of output signal readings to dry the tube. determining a light intensity value; after determining the dry tube light intensity value, controlling operation of a pump to prime the outlet line with fluid from at least one fluid source; and monitoring the output signal, the output signal indicating that the light intensity value has fallen below a primed line threshold indicating that the exit line has been primed. When the system is configured to stop operation of the pump , the primed line threshold is dependent on the dry tube light intensity value . 11. The system of claim 10, wherein the primed line threshold is calculated by adding a constant to a percentage of the dry tube light intensity value. The maximum light intensity value is compared with a minimum value of the dry tube light intensity values, and the dry tube light intensity value is set as the minimum value when the maximum light intensity value is below the minimum value. The system according to claim 10. The system further includes a displacement volume sensing assembly, and the controller is further configured to generate a notification when the displacement volume sensing assembly indicates that the volume of fluid displaced is greater than a predetermined threshold. 11. The system of claim 10. 14. The controller is configured to coordinate resumption of operation of the pump upon receipt of user input from a user interface of the system indicating that the outlet line is not yet fully primed. system described in. 11. The system of claim 10, wherein a portion of the pump is included in the fluid transfer set. 11. The system of claim 10, wherein the at least one illuminator includes a first LED positioned at an angle non-parallel to the optical axis of the sensor. 16. The at least one illuminator includes a second LED and a third LED, and the axis of the second LED and the axis of the third LED are parallel to the optical axis of the sensor. system described in. A fluid pump system comprising:
pump and
a conduit condition detector having a receptacle, at least one sensor, and at least one illuminator;
a fluid transfer set including a conduit configured to mate with the receptacle;
a controller in data communication with the conduit condition detector, the controller energizing at least one of the at least one illuminator multiple times when the conduit is attached to the receptacle; monitoring an output signal from one sensor to determine a light intensity value for an unprimed conduit based on a maximum light intensity value from the output signal; delivering a fluid from a source to the conduit; powering at least one of the one or more illuminators and monitoring the output signal, the output signal determining whether the light intensity value is the priming source; The system is configured to stop operation of the pump when indicating that the light intensity value of the conduit has fallen below a threshold value calculated based on a light intensity value of a conduit that has not been used. 19. The system of claim 18, wherein the threshold is calculated by adding a constant to a percentage of the unprimed conduit light intensity value. 19. The system of claim 18, wherein the unprimed conduit light intensity value is determined by applying at least one limit to the maximum light intensity value. The system further includes a displacement volume sensing assembly, and the controller is further configured to generate a notification when the displacement volume sensing assembly indicates that the volume of fluid displaced is greater than a predetermined threshold. 20. The system of claim 18. 22. The controller is configured to command further operation of the pump upon receipt of user input from a user interface of the system indicating that the conduit is not yet fully primed. system. 23. The system of claim 22, wherein the pump is a pneumatic diaphragm pump. 19. The system of claim 18, wherein a portion of the pump is included in the fluid transfer set. 19. The system of claim 18, wherein the at least one illuminator includes a first LED positioned at an angle non-parallel to the optical axis of the sensor. The at least one illuminator includes a second LED and a third LED, the second LED D and the third LED D being opposite the portion of the receptacle in which the sensor is disposed. 26. The system of claim 25, wherein the system is located on a first side of the receptacle at . A fluid pump system comprising:
pump and
a conduit condition detector having a receptacle, at least one sensor, and at least one illuminator;
a fluid transfer set including a conduit configured to mate with the receptacle;
a controller in data communication with a conduit condition detector, wherein at least one of the at least one illuminator is connected to the conduit while the conduit is attached to the receptacle but before fluid is delivered by the pump; monitoring an output signal from the at least one sensor to determine an unprimed conduit light intensity value using a maximum light intensity value indicated by the output signal; controlling operation to deliver fluid from at least one fluid source to the conduit; powering at least one of the one or more illuminators and monitoring the output signal; , the system is configured to stop operation of the pump when the light intensity value indicates that the light intensity value falls below a threshold value calculated based on the light intensity value of the unprimed conduit. Claim: wherein the controller is further configured to power at least one of the at least one illuminator and monitor the output signal to ensure that the conduit is not primed. The system according to item 27. 28. The system of claim 27, wherein the controller is configured to determine a light intensity value for the unprimed conduit by subjecting the maximum light intensity value to at least one limit.

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